diff -r d59bea55db9b -r c445c931472f src/colamd/colamd.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/colamd/colamd.c Mon Dec 06 13:09:21 2010 +0100 @@ -0,0 +1,3622 @@ +/* ========================================================================== */ +/* === colamd/symamd - a sparse matrix column ordering algorithm ============ */ +/* ========================================================================== */ + +/* COLAMD / SYMAMD + + colamd: an approximate minimum degree column ordering algorithm, + for LU factorization of symmetric or unsymmetric matrices, + QR factorization, least squares, interior point methods for + linear programming problems, and other related problems. + + symamd: an approximate minimum degree ordering algorithm for Cholesky + factorization of symmetric matrices. + + Purpose: + + Colamd computes a permutation Q such that the Cholesky factorization of + (AQ)'(AQ) has less fill-in and requires fewer floating point operations + than A'A. This also provides a good ordering for sparse partial + pivoting methods, P(AQ) = LU, where Q is computed prior to numerical + factorization, and P is computed during numerical factorization via + conventional partial pivoting with row interchanges. Colamd is the + column ordering method used in SuperLU, part of the ScaLAPACK library. + It is also available as built-in function in MATLAB Version 6, + available from MathWorks, Inc. (http://www.mathworks.com). This + routine can be used in place of colmmd in MATLAB. + + Symamd computes a permutation P of a symmetric matrix A such that the + Cholesky factorization of PAP' has less fill-in and requires fewer + floating point operations than A. Symamd constructs a matrix M such + that M'M has the same nonzero pattern of A, and then orders the columns + of M using colmmd. The column ordering of M is then returned as the + row and column ordering P of A. + + Authors: + + The authors of the code itself are Stefan I. Larimore and Timothy A. + Davis (davis at cise.ufl.edu), University of Florida. The algorithm was + developed in collaboration with John Gilbert, Xerox PARC, and Esmond + Ng, Oak Ridge National Laboratory. + + Acknowledgements: + + This work was supported by the National Science Foundation, under + grants DMS-9504974 and DMS-9803599. + + Copyright and License: + + Copyright (c) 1998-2007, Timothy A. Davis, All Rights Reserved. + COLAMD is also available under alternate licenses, contact T. Davis + for details. + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 + USA + + Permission is hereby granted to use or copy this program under the + terms of the GNU LGPL, provided that the Copyright, this License, + and the Availability of the original version is retained on all copies. + User documentation of any code that uses this code or any modified + version of this code must cite the Copyright, this License, the + Availability note, and "Used by permission." Permission to modify + the code and to distribute modified code is granted, provided the + Copyright, this License, and the Availability note are retained, + and a notice that the code was modified is included. + + Availability: + + The colamd/symamd library is available at + + http://www.cise.ufl.edu/research/sparse/colamd/ + + This is the http://www.cise.ufl.edu/research/sparse/colamd/colamd.c + file. It requires the colamd.h file. It is required by the colamdmex.c + and symamdmex.c files, for the MATLAB interface to colamd and symamd. + Appears as ACM Algorithm 836. + + See the ChangeLog file for changes since Version 1.0. + + References: + + T. A. Davis, J. R. Gilbert, S. Larimore, E. Ng, An approximate column + minimum degree ordering algorithm, ACM Transactions on Mathematical + Software, vol. 30, no. 3., pp. 353-376, 2004. + + T. A. Davis, J. R. Gilbert, S. Larimore, E. Ng, Algorithm 836: COLAMD, + an approximate column minimum degree ordering algorithm, ACM + Transactions on Mathematical Software, vol. 30, no. 3., pp. 377-380, + 2004. + +*/ + +/* ========================================================================== */ +/* === Description of user-callable routines ================================ */ +/* ========================================================================== */ + +/* COLAMD includes both int and UF_long versions of all its routines. The + * description below is for the int version. For UF_long, all int arguments + * become UF_long. UF_long is normally defined as long, except for WIN64. + + ---------------------------------------------------------------------------- + colamd_recommended: + ---------------------------------------------------------------------------- + + C syntax: + + #include "colamd.h" + size_t colamd_recommended (int nnz, int n_row, int n_col) ; + size_t colamd_l_recommended (UF_long nnz, UF_long n_row, + UF_long n_col) ; + + Purpose: + + Returns recommended value of Alen for use by colamd. Returns 0 + if any input argument is negative. The use of this routine + is optional. Not needed for symamd, which dynamically allocates + its own memory. + + Note that in v2.4 and earlier, these routines returned int or long. + They now return a value of type size_t. + + Arguments (all input arguments): + + int nnz ; Number of nonzeros in the matrix A. This must + be the same value as p [n_col] in the call to + colamd - otherwise you will get a wrong value + of the recommended memory to use. + + int n_row ; Number of rows in the matrix A. + + int n_col ; Number of columns in the matrix A. + + ---------------------------------------------------------------------------- + colamd_set_defaults: + ---------------------------------------------------------------------------- + + C syntax: + + #include "colamd.h" + colamd_set_defaults (double knobs [COLAMD_KNOBS]) ; + colamd_l_set_defaults (double knobs [COLAMD_KNOBS]) ; + + Purpose: + + Sets the default parameters. The use of this routine is optional. + + Arguments: + + double knobs [COLAMD_KNOBS] ; Output only. + + NOTE: the meaning of the dense row/col knobs has changed in v2.4 + + knobs [0] and knobs [1] control dense row and col detection: + + Colamd: rows with more than + max (16, knobs [COLAMD_DENSE_ROW] * sqrt (n_col)) + entries are removed prior to ordering. Columns with more than + max (16, knobs [COLAMD_DENSE_COL] * sqrt (MIN (n_row,n_col))) + entries are removed prior to + ordering, and placed last in the output column ordering. + + Symamd: uses only knobs [COLAMD_DENSE_ROW], which is knobs [0]. + Rows and columns with more than + max (16, knobs [COLAMD_DENSE_ROW] * sqrt (n)) + entries are removed prior to ordering, and placed last in the + output ordering. + + COLAMD_DENSE_ROW and COLAMD_DENSE_COL are defined as 0 and 1, + respectively, in colamd.h. Default values of these two knobs + are both 10. Currently, only knobs [0] and knobs [1] are + used, but future versions may use more knobs. If so, they will + be properly set to their defaults by the future version of + colamd_set_defaults, so that the code that calls colamd will + not need to change, assuming that you either use + colamd_set_defaults, or pass a (double *) NULL pointer as the + knobs array to colamd or symamd. + + knobs [2]: aggressive absorption + + knobs [COLAMD_AGGRESSIVE] controls whether or not to do + aggressive absorption during the ordering. Default is TRUE. + + + ---------------------------------------------------------------------------- + colamd: + ---------------------------------------------------------------------------- + + C syntax: + + #include "colamd.h" + int colamd (int n_row, int n_col, int Alen, int *A, int *p, + double knobs [COLAMD_KNOBS], int stats [COLAMD_STATS]) ; + UF_long colamd_l (UF_long n_row, UF_long n_col, UF_long Alen, + UF_long *A, UF_long *p, double knobs [COLAMD_KNOBS], + UF_long stats [COLAMD_STATS]) ; + + Purpose: + + Computes a column ordering (Q) of A such that P(AQ)=LU or + (AQ)'AQ=LL' have less fill-in and require fewer floating point + operations than factorizing the unpermuted matrix A or A'A, + respectively. + + Returns: + + TRUE (1) if successful, FALSE (0) otherwise. + + Arguments: + + int n_row ; Input argument. + + Number of rows in the matrix A. + Restriction: n_row >= 0. + Colamd returns FALSE if n_row is negative. + + int n_col ; Input argument. + + Number of columns in the matrix A. + Restriction: n_col >= 0. + Colamd returns FALSE if n_col is negative. + + int Alen ; Input argument. + + Restriction (see note): + Alen >= 2*nnz + 6*(n_col+1) + 4*(n_row+1) + n_col + Colamd returns FALSE if these conditions are not met. + + Note: this restriction makes an modest assumption regarding + the size of the two typedef's structures in colamd.h. + We do, however, guarantee that + + Alen >= colamd_recommended (nnz, n_row, n_col) + + will be sufficient. Note: the macro version does not check + for integer overflow, and thus is not recommended. Use + the colamd_recommended routine instead. + + int A [Alen] ; Input argument, undefined on output. + + A is an integer array of size Alen. Alen must be at least as + large as the bare minimum value given above, but this is very + low, and can result in excessive run time. For best + performance, we recommend that Alen be greater than or equal to + colamd_recommended (nnz, n_row, n_col), which adds + nnz/5 to the bare minimum value given above. + + On input, the row indices of the entries in column c of the + matrix are held in A [(p [c]) ... (p [c+1]-1)]. The row indices + in a given column c need not be in ascending order, and + duplicate row indices may be be present. However, colamd will + work a little faster if both of these conditions are met + (Colamd puts the matrix into this format, if it finds that the + the conditions are not met). + + The matrix is 0-based. That is, rows are in the range 0 to + n_row-1, and columns are in the range 0 to n_col-1. Colamd + returns FALSE if any row index is out of range. + + The contents of A are modified during ordering, and are + undefined on output. + + int p [n_col+1] ; Both input and output argument. + + p is an integer array of size n_col+1. On input, it holds the + "pointers" for the column form of the matrix A. Column c of + the matrix A is held in A [(p [c]) ... (p [c+1]-1)]. The first + entry, p [0], must be zero, and p [c] <= p [c+1] must hold + for all c in the range 0 to n_col-1. The value p [n_col] is + thus the total number of entries in the pattern of the matrix A. + Colamd returns FALSE if these conditions are not met. + + On output, if colamd returns TRUE, the array p holds the column + permutation (Q, for P(AQ)=LU or (AQ)'(AQ)=LL'), where p [0] is + the first column index in the new ordering, and p [n_col-1] is + the last. That is, p [k] = j means that column j of A is the + kth pivot column, in AQ, where k is in the range 0 to n_col-1 + (p [0] = j means that column j of A is the first column in AQ). + + If colamd returns FALSE, then no permutation is returned, and + p is undefined on output. + + double knobs [COLAMD_KNOBS] ; Input argument. + + See colamd_set_defaults for a description. + + int stats [COLAMD_STATS] ; Output argument. + + Statistics on the ordering, and error status. + See colamd.h for related definitions. + Colamd returns FALSE if stats is not present. + + stats [0]: number of dense or empty rows ignored. + + stats [1]: number of dense or empty columns ignored (and + ordered last in the output permutation p) + Note that a row can become "empty" if it + contains only "dense" and/or "empty" columns, + and similarly a column can become "empty" if it + only contains "dense" and/or "empty" rows. + + stats [2]: number of garbage collections performed. + This can be excessively high if Alen is close + to the minimum required value. + + stats [3]: status code. < 0 is an error code. + > 1 is a warning or notice. + + 0 OK. Each column of the input matrix contained + row indices in increasing order, with no + duplicates. + + 1 OK, but columns of input matrix were jumbled + (unsorted columns or duplicate entries). Colamd + had to do some extra work to sort the matrix + first and remove duplicate entries, but it + still was able to return a valid permutation + (return value of colamd was TRUE). + + stats [4]: highest numbered column that + is unsorted or has duplicate + entries. + stats [5]: last seen duplicate or + unsorted row index. + stats [6]: number of duplicate or + unsorted row indices. + + -1 A is a null pointer + + -2 p is a null pointer + + -3 n_row is negative + + stats [4]: n_row + + -4 n_col is negative + + stats [4]: n_col + + -5 number of nonzeros in matrix is negative + + stats [4]: number of nonzeros, p [n_col] + + -6 p [0] is nonzero + + stats [4]: p [0] + + -7 A is too small + + stats [4]: required size + stats [5]: actual size (Alen) + + -8 a column has a negative number of entries + + stats [4]: column with < 0 entries + stats [5]: number of entries in col + + -9 a row index is out of bounds + + stats [4]: column with bad row index + stats [5]: bad row index + stats [6]: n_row, # of rows of matrx + + -10 (unused; see symamd.c) + + -999 (unused; see symamd.c) + + Future versions may return more statistics in the stats array. + + Example: + + See http://www.cise.ufl.edu/research/sparse/colamd/example.c + for a complete example. + + To order the columns of a 5-by-4 matrix with 11 nonzero entries in + the following nonzero pattern + + x 0 x 0 + x 0 x x + 0 x x 0 + 0 0 x x + x x 0 0 + + with default knobs and no output statistics, do the following: + + #include "colamd.h" + #define ALEN 100 + int A [ALEN] = {0, 1, 4, 2, 4, 0, 1, 2, 3, 1, 3} ; + int p [ ] = {0, 3, 5, 9, 11} ; + int stats [COLAMD_STATS] ; + colamd (5, 4, ALEN, A, p, (double *) NULL, stats) ; + + The permutation is returned in the array p, and A is destroyed. + + ---------------------------------------------------------------------------- + symamd: + ---------------------------------------------------------------------------- + + C syntax: + + #include "colamd.h" + int symamd (int n, int *A, int *p, int *perm, + double knobs [COLAMD_KNOBS], int stats [COLAMD_STATS], + void (*allocate) (size_t, size_t), void (*release) (void *)) ; + UF_long symamd_l (UF_long n, UF_long *A, UF_long *p, UF_long *perm, + double knobs [COLAMD_KNOBS], UF_long stats [COLAMD_STATS], + void (*allocate) (size_t, size_t), void (*release) (void *)) ; + + Purpose: + + The symamd routine computes an ordering P of a symmetric sparse + matrix A such that the Cholesky factorization PAP' = LL' remains + sparse. It is based on a column ordering of a matrix M constructed + so that the nonzero pattern of M'M is the same as A. The matrix A + is assumed to be symmetric; only the strictly lower triangular part + is accessed. You must pass your selected memory allocator (usually + calloc/free or mxCalloc/mxFree) to symamd, for it to allocate + memory for the temporary matrix M. + + Returns: + + TRUE (1) if successful, FALSE (0) otherwise. + + Arguments: + + int n ; Input argument. + + Number of rows and columns in the symmetrix matrix A. + Restriction: n >= 0. + Symamd returns FALSE if n is negative. + + int A [nnz] ; Input argument. + + A is an integer array of size nnz, where nnz = p [n]. + + The row indices of the entries in column c of the matrix are + held in A [(p [c]) ... (p [c+1]-1)]. The row indices in a + given column c need not be in ascending order, and duplicate + row indices may be present. However, symamd will run faster + if the columns are in sorted order with no duplicate entries. + + The matrix is 0-based. That is, rows are in the range 0 to + n-1, and columns are in the range 0 to n-1. Symamd + returns FALSE if any row index is out of range. + + The contents of A are not modified. + + int p [n+1] ; Input argument. + + p is an integer array of size n+1. On input, it holds the + "pointers" for the column form of the matrix A. Column c of + the matrix A is held in A [(p [c]) ... (p [c+1]-1)]. The first + entry, p [0], must be zero, and p [c] <= p [c+1] must hold + for all c in the range 0 to n-1. The value p [n] is + thus the total number of entries in the pattern of the matrix A. + Symamd returns FALSE if these conditions are not met. + + The contents of p are not modified. + + int perm [n+1] ; Output argument. + + On output, if symamd returns TRUE, the array perm holds the + permutation P, where perm [0] is the first index in the new + ordering, and perm [n-1] is the last. That is, perm [k] = j + means that row and column j of A is the kth column in PAP', + where k is in the range 0 to n-1 (perm [0] = j means + that row and column j of A are the first row and column in + PAP'). The array is used as a workspace during the ordering, + which is why it must be of length n+1, not just n. + + double knobs [COLAMD_KNOBS] ; Input argument. + + See colamd_set_defaults for a description. + + int stats [COLAMD_STATS] ; Output argument. + + Statistics on the ordering, and error status. + See colamd.h for related definitions. + Symamd returns FALSE if stats is not present. + + stats [0]: number of dense or empty row and columns ignored + (and ordered last in the output permutation + perm). Note that a row/column can become + "empty" if it contains only "dense" and/or + "empty" columns/rows. + + stats [1]: (same as stats [0]) + + stats [2]: number of garbage collections performed. + + stats [3]: status code. < 0 is an error code. + > 1 is a warning or notice. + + 0 OK. Each column of the input matrix contained + row indices in increasing order, with no + duplicates. + + 1 OK, but columns of input matrix were jumbled + (unsorted columns or duplicate entries). Symamd + had to do some extra work to sort the matrix + first and remove duplicate entries, but it + still was able to return a valid permutation + (return value of symamd was TRUE). + + stats [4]: highest numbered column that + is unsorted or has duplicate + entries. + stats [5]: last seen duplicate or + unsorted row index. + stats [6]: number of duplicate or + unsorted row indices. + + -1 A is a null pointer + + -2 p is a null pointer + + -3 (unused, see colamd.c) + + -4 n is negative + + stats [4]: n + + -5 number of nonzeros in matrix is negative + + stats [4]: # of nonzeros (p [n]). + + -6 p [0] is nonzero + + stats [4]: p [0] + + -7 (unused) + + -8 a column has a negative number of entries + + stats [4]: column with < 0 entries + stats [5]: number of entries in col + + -9 a row index is out of bounds + + stats [4]: column with bad row index + stats [5]: bad row index + stats [6]: n_row, # of rows of matrx + + -10 out of memory (unable to allocate temporary + workspace for M or count arrays using the + "allocate" routine passed into symamd). + + Future versions may return more statistics in the stats array. + + void * (*allocate) (size_t, size_t) + + A pointer to a function providing memory allocation. The + allocated memory must be returned initialized to zero. For a + C application, this argument should normally be a pointer to + calloc. For a MATLAB mexFunction, the routine mxCalloc is + passed instead. + + void (*release) (size_t, size_t) + + A pointer to a function that frees memory allocated by the + memory allocation routine above. For a C application, this + argument should normally be a pointer to free. For a MATLAB + mexFunction, the routine mxFree is passed instead. + + + ---------------------------------------------------------------------------- + colamd_report: + ---------------------------------------------------------------------------- + + C syntax: + + #include "colamd.h" + colamd_report (int stats [COLAMD_STATS]) ; + colamd_l_report (UF_long stats [COLAMD_STATS]) ; + + Purpose: + + Prints the error status and statistics recorded in the stats + array on the standard error output (for a standard C routine) + or on the MATLAB output (for a mexFunction). + + Arguments: + + int stats [COLAMD_STATS] ; Input only. Statistics from colamd. + + + ---------------------------------------------------------------------------- + symamd_report: + ---------------------------------------------------------------------------- + + C syntax: + + #include "colamd.h" + symamd_report (int stats [COLAMD_STATS]) ; + symamd_l_report (UF_long stats [COLAMD_STATS]) ; + + Purpose: + + Prints the error status and statistics recorded in the stats + array on the standard error output (for a standard C routine) + or on the MATLAB output (for a mexFunction). + + Arguments: + + int stats [COLAMD_STATS] ; Input only. Statistics from symamd. + + +*/ + +/* ========================================================================== */ +/* === Scaffolding code definitions ======================================== */ +/* ========================================================================== */ + +/* Ensure that debugging is turned off: */ +#ifndef NDEBUG +#define NDEBUG +#endif + +/* turn on debugging by uncommenting the following line + #undef NDEBUG +*/ + +/* + Our "scaffolding code" philosophy: In our opinion, well-written library + code should keep its "debugging" code, and just normally have it turned off + by the compiler so as not to interfere with performance. This serves + several purposes: + + (1) assertions act as comments to the reader, telling you what the code + expects at that point. All assertions will always be true (unless + there really is a bug, of course). + + (2) leaving in the scaffolding code assists anyone who would like to modify + the code, or understand the algorithm (by reading the debugging output, + one can get a glimpse into what the code is doing). + + (3) (gasp!) for actually finding bugs. This code has been heavily tested + and "should" be fully functional and bug-free ... but you never know... + + The code will become outrageously slow when debugging is + enabled. To control the level of debugging output, set an environment + variable D to 0 (little), 1 (some), 2, 3, or 4 (lots). When debugging, + you should see the following message on the standard output: + + colamd: debug version, D = 1 (THIS WILL BE SLOW!) + + or a similar message for symamd. If you don't, then debugging has not + been enabled. + +*/ + +/* ========================================================================== */ +/* === Include files ======================================================== */ +/* ========================================================================== */ + +#include "colamd.h" + +#if 0 /* by mao */ +#include +#include + +#ifdef MATLAB_MEX_FILE +#include "mex.h" +#include "matrix.h" +#endif /* MATLAB_MEX_FILE */ + +#if !defined (NPRINT) || !defined (NDEBUG) +#include +#endif + +#ifndef NULL +#define NULL ((void *) 0) +#endif +#endif + +/* ========================================================================== */ +/* === int or UF_long ======================================================= */ +/* ========================================================================== */ + +#if 0 /* by mao */ +/* define UF_long */ +#include "UFconfig.h" +#endif + +#ifdef DLONG + +#define Int UF_long +#define ID UF_long_id +#define Int_MAX UF_long_max + +#define COLAMD_recommended colamd_l_recommended +#define COLAMD_set_defaults colamd_l_set_defaults +#define COLAMD_MAIN colamd_l +#define SYMAMD_MAIN symamd_l +#define COLAMD_report colamd_l_report +#define SYMAMD_report symamd_l_report + +#else + +#define Int int +#define ID "%d" +#define Int_MAX INT_MAX + +#define COLAMD_recommended colamd_recommended +#define COLAMD_set_defaults colamd_set_defaults +#define COLAMD_MAIN colamd +#define SYMAMD_MAIN symamd +#define COLAMD_report colamd_report +#define SYMAMD_report symamd_report + +#endif + +/* ========================================================================== */ +/* === Row and Column structures ============================================ */ +/* ========================================================================== */ + +/* User code that makes use of the colamd/symamd routines need not directly */ +/* reference these structures. They are used only for colamd_recommended. */ + +typedef struct Colamd_Col_struct +{ + Int start ; /* index for A of first row in this column, or DEAD */ + /* if column is dead */ + Int length ; /* number of rows in this column */ + union + { + Int thickness ; /* number of original columns represented by this */ + /* col, if the column is alive */ + Int parent ; /* parent in parent tree super-column structure, if */ + /* the column is dead */ + } shared1 ; + union + { + Int score ; /* the score used to maintain heap, if col is alive */ + Int order ; /* pivot ordering of this column, if col is dead */ + } shared2 ; + union + { + Int headhash ; /* head of a hash bucket, if col is at the head of */ + /* a degree list */ + Int hash ; /* hash value, if col is not in a degree list */ + Int prev ; /* previous column in degree list, if col is in a */ + /* degree list (but not at the head of a degree list) */ + } shared3 ; + union + { + Int degree_next ; /* next column, if col is in a degree list */ + Int hash_next ; /* next column, if col is in a hash list */ + } shared4 ; + +} Colamd_Col ; + +typedef struct Colamd_Row_struct +{ + Int start ; /* index for A of first col in this row */ + Int length ; /* number of principal columns in this row */ + union + { + Int degree ; /* number of principal & non-principal columns in row */ + Int p ; /* used as a row pointer in init_rows_cols () */ + } shared1 ; + union + { + Int mark ; /* for computing set differences and marking dead rows*/ + Int first_column ;/* first column in row (used in garbage collection) */ + } shared2 ; + +} Colamd_Row ; + +/* ========================================================================== */ +/* === Definitions ========================================================== */ +/* ========================================================================== */ + +/* Routines are either PUBLIC (user-callable) or PRIVATE (not user-callable) */ +#define PUBLIC +#define PRIVATE static + +#define DENSE_DEGREE(alpha,n) \ + ((Int) MAX (16.0, (alpha) * sqrt ((double) (n)))) + +#define MAX(a,b) (((a) > (b)) ? (a) : (b)) +#define MIN(a,b) (((a) < (b)) ? (a) : (b)) + +#define ONES_COMPLEMENT(r) (-(r)-1) + +/* -------------------------------------------------------------------------- */ +/* Change for version 2.1: define TRUE and FALSE only if not yet defined */ +/* -------------------------------------------------------------------------- */ + +#ifndef TRUE +#define TRUE (1) +#endif + +#ifndef FALSE +#define FALSE (0) +#endif + +/* -------------------------------------------------------------------------- */ + +#define EMPTY (-1) + +/* Row and column status */ +#define ALIVE (0) +#define DEAD (-1) + +/* Column status */ +#define DEAD_PRINCIPAL (-1) +#define DEAD_NON_PRINCIPAL (-2) + +/* Macros for row and column status update and checking. */ +#define ROW_IS_DEAD(r) ROW_IS_MARKED_DEAD (Row[r].shared2.mark) +#define ROW_IS_MARKED_DEAD(row_mark) (row_mark < ALIVE) +#define ROW_IS_ALIVE(r) (Row [r].shared2.mark >= ALIVE) +#define COL_IS_DEAD(c) (Col [c].start < ALIVE) +#define COL_IS_ALIVE(c) (Col [c].start >= ALIVE) +#define COL_IS_DEAD_PRINCIPAL(c) (Col [c].start == DEAD_PRINCIPAL) +#define KILL_ROW(r) { Row [r].shared2.mark = DEAD ; } +#define KILL_PRINCIPAL_COL(c) { Col [c].start = DEAD_PRINCIPAL ; } +#define KILL_NON_PRINCIPAL_COL(c) { Col [c].start = DEAD_NON_PRINCIPAL ; } + +/* ========================================================================== */ +/* === Colamd reporting mechanism =========================================== */ +/* ========================================================================== */ + +#if defined (MATLAB_MEX_FILE) || defined (MATHWORKS) +/* In MATLAB, matrices are 1-based to the user, but 0-based internally */ +#define INDEX(i) ((i)+1) +#else +/* In C, matrices are 0-based and indices are reported as such in *_report */ +#define INDEX(i) (i) +#endif + +/* All output goes through the PRINTF macro. */ +#define PRINTF(params) { if (colamd_printf != NULL) (void) colamd_printf params ; } + +/* ========================================================================== */ +/* === Prototypes of PRIVATE routines ======================================= */ +/* ========================================================================== */ + +PRIVATE Int init_rows_cols +( + Int n_row, + Int n_col, + Colamd_Row Row [], + Colamd_Col Col [], + Int A [], + Int p [], + Int stats [COLAMD_STATS] +) ; + +PRIVATE void init_scoring +( + Int n_row, + Int n_col, + Colamd_Row Row [], + Colamd_Col Col [], + Int A [], + Int head [], + double knobs [COLAMD_KNOBS], + Int *p_n_row2, + Int *p_n_col2, + Int *p_max_deg +) ; + +PRIVATE Int find_ordering +( + Int n_row, + Int n_col, + Int Alen, + Colamd_Row Row [], + Colamd_Col Col [], + Int A [], + Int head [], + Int n_col2, + Int max_deg, + Int pfree, + Int aggressive +) ; + +PRIVATE void order_children +( + Int n_col, + Colamd_Col Col [], + Int p [] +) ; + +PRIVATE void detect_super_cols +( + +#ifndef NDEBUG + Int n_col, + Colamd_Row Row [], +#endif /* NDEBUG */ + + Colamd_Col Col [], + Int A [], + Int head [], + Int row_start, + Int row_length +) ; + +PRIVATE Int garbage_collection +( + Int n_row, + Int n_col, + Colamd_Row Row [], + Colamd_Col Col [], + Int A [], + Int *pfree +) ; + +PRIVATE Int clear_mark +( + Int tag_mark, + Int max_mark, + Int n_row, + Colamd_Row Row [] +) ; + +PRIVATE void print_report +( + char *method, + Int stats [COLAMD_STATS] +) ; + +/* ========================================================================== */ +/* === Debugging prototypes and definitions ================================= */ +/* ========================================================================== */ + +#ifndef NDEBUG + +#if 0 /* by mao */ +#include +#endif + +/* colamd_debug is the *ONLY* global variable, and is only */ +/* present when debugging */ + +PRIVATE Int colamd_debug = 0 ; /* debug print level */ + +#define DEBUG0(params) { PRINTF (params) ; } +#define DEBUG1(params) { if (colamd_debug >= 1) PRINTF (params) ; } +#define DEBUG2(params) { if (colamd_debug >= 2) PRINTF (params) ; } +#define DEBUG3(params) { if (colamd_debug >= 3) PRINTF (params) ; } +#define DEBUG4(params) { if (colamd_debug >= 4) PRINTF (params) ; } + +#if 0 /* by mao */ +#ifdef MATLAB_MEX_FILE +#define ASSERT(expression) (mxAssert ((expression), "")) +#else +#define ASSERT(expression) (assert (expression)) +#endif /* MATLAB_MEX_FILE */ +#else +#define ASSERT xassert +#endif + +PRIVATE void colamd_get_debug /* gets the debug print level from getenv */ +( + char *method +) ; + +PRIVATE void debug_deg_lists +( + Int n_row, + Int n_col, + Colamd_Row Row [], + Colamd_Col Col [], + Int head [], + Int min_score, + Int should, + Int max_deg +) ; + +PRIVATE void debug_mark +( + Int n_row, + Colamd_Row Row [], + Int tag_mark, + Int max_mark +) ; + +PRIVATE void debug_matrix +( + Int n_row, + Int n_col, + Colamd_Row Row [], + Colamd_Col Col [], + Int A [] +) ; + +PRIVATE void debug_structures +( + Int n_row, + Int n_col, + Colamd_Row Row [], + Colamd_Col Col [], + Int A [], + Int n_col2 +) ; + +#else /* NDEBUG */ + +/* === No debugging ========================================================= */ + +#define DEBUG0(params) ; +#define DEBUG1(params) ; +#define DEBUG2(params) ; +#define DEBUG3(params) ; +#define DEBUG4(params) ; + +#define ASSERT(expression) + +#endif /* NDEBUG */ + +/* ========================================================================== */ +/* === USER-CALLABLE ROUTINES: ============================================== */ +/* ========================================================================== */ + +/* ========================================================================== */ +/* === colamd_recommended =================================================== */ +/* ========================================================================== */ + +/* + The colamd_recommended routine returns the suggested size for Alen. This + value has been determined to provide good balance between the number of + garbage collections and the memory requirements for colamd. If any + argument is negative, or if integer overflow occurs, a 0 is returned as an + error condition. 2*nnz space is required for the row and column + indices of the matrix. COLAMD_C (n_col) + COLAMD_R (n_row) space is + required for the Col and Row arrays, respectively, which are internal to + colamd (roughly 6*n_col + 4*n_row). An additional n_col space is the + minimal amount of "elbow room", and nnz/5 more space is recommended for + run time efficiency. + + Alen is approximately 2.2*nnz + 7*n_col + 4*n_row + 10. + + This function is not needed when using symamd. +*/ + +/* add two values of type size_t, and check for integer overflow */ +static size_t t_add (size_t a, size_t b, int *ok) +{ + (*ok) = (*ok) && ((a + b) >= MAX (a,b)) ; + return ((*ok) ? (a + b) : 0) ; +} + +/* compute a*k where k is a small integer, and check for integer overflow */ +static size_t t_mult (size_t a, size_t k, int *ok) +{ + size_t i, s = 0 ; + for (i = 0 ; i < k ; i++) + { + s = t_add (s, a, ok) ; + } + return (s) ; +} + +/* size of the Col and Row structures */ +#define COLAMD_C(n_col,ok) \ + ((t_mult (t_add (n_col, 1, ok), sizeof (Colamd_Col), ok) / sizeof (Int))) + +#define COLAMD_R(n_row,ok) \ + ((t_mult (t_add (n_row, 1, ok), sizeof (Colamd_Row), ok) / sizeof (Int))) + + +PUBLIC size_t COLAMD_recommended /* returns recommended value of Alen. */ +( + /* === Parameters ======================================================= */ + + Int nnz, /* number of nonzeros in A */ + Int n_row, /* number of rows in A */ + Int n_col /* number of columns in A */ +) +{ + size_t s, c, r ; + int ok = TRUE ; + if (nnz < 0 || n_row < 0 || n_col < 0) + { + return (0) ; + } + s = t_mult (nnz, 2, &ok) ; /* 2*nnz */ + c = COLAMD_C (n_col, &ok) ; /* size of column structures */ + r = COLAMD_R (n_row, &ok) ; /* size of row structures */ + s = t_add (s, c, &ok) ; + s = t_add (s, r, &ok) ; + s = t_add (s, n_col, &ok) ; /* elbow room */ + s = t_add (s, nnz/5, &ok) ; /* elbow room */ + ok = ok && (s < Int_MAX) ; + return (ok ? s : 0) ; +} + + +/* ========================================================================== */ +/* === colamd_set_defaults ================================================== */ +/* ========================================================================== */ + +/* + The colamd_set_defaults routine sets the default values of the user- + controllable parameters for colamd and symamd: + + Colamd: rows with more than max (16, knobs [0] * sqrt (n_col)) + entries are removed prior to ordering. Columns with more than + max (16, knobs [1] * sqrt (MIN (n_row,n_col))) entries are removed + prior to ordering, and placed last in the output column ordering. + + Symamd: Rows and columns with more than max (16, knobs [0] * sqrt (n)) + entries are removed prior to ordering, and placed last in the + output ordering. + + knobs [0] dense row control + + knobs [1] dense column control + + knobs [2] if nonzero, do aggresive absorption + + knobs [3..19] unused, but future versions might use this + +*/ + +PUBLIC void COLAMD_set_defaults +( + /* === Parameters ======================================================= */ + + double knobs [COLAMD_KNOBS] /* knob array */ +) +{ + /* === Local variables ================================================== */ + + Int i ; + + if (!knobs) + { + return ; /* no knobs to initialize */ + } + for (i = 0 ; i < COLAMD_KNOBS ; i++) + { + knobs [i] = 0 ; + } + knobs [COLAMD_DENSE_ROW] = 10 ; + knobs [COLAMD_DENSE_COL] = 10 ; + knobs [COLAMD_AGGRESSIVE] = TRUE ; /* default: do aggressive absorption*/ +} + + +/* ========================================================================== */ +/* === symamd =============================================================== */ +/* ========================================================================== */ + +PUBLIC Int SYMAMD_MAIN /* return TRUE if OK, FALSE otherwise */ +( + /* === Parameters ======================================================= */ + + Int n, /* number of rows and columns of A */ + Int A [], /* row indices of A */ + Int p [], /* column pointers of A */ + Int perm [], /* output permutation, size n+1 */ + double knobs [COLAMD_KNOBS], /* parameters (uses defaults if NULL) */ + Int stats [COLAMD_STATS], /* output statistics and error codes */ + void * (*allocate) (size_t, size_t), + /* pointer to calloc (ANSI C) or */ + /* mxCalloc (for MATLAB mexFunction) */ + void (*release) (void *) + /* pointer to free (ANSI C) or */ + /* mxFree (for MATLAB mexFunction) */ +) +{ + /* === Local variables ================================================== */ + + Int *count ; /* length of each column of M, and col pointer*/ + Int *mark ; /* mark array for finding duplicate entries */ + Int *M ; /* row indices of matrix M */ + size_t Mlen ; /* length of M */ + Int n_row ; /* number of rows in M */ + Int nnz ; /* number of entries in A */ + Int i ; /* row index of A */ + Int j ; /* column index of A */ + Int k ; /* row index of M */ + Int mnz ; /* number of nonzeros in M */ + Int pp ; /* index into a column of A */ + Int last_row ; /* last row seen in the current column */ + Int length ; /* number of nonzeros in a column */ + + double cknobs [COLAMD_KNOBS] ; /* knobs for colamd */ + double default_knobs [COLAMD_KNOBS] ; /* default knobs for colamd */ + +#ifndef NDEBUG + colamd_get_debug ("symamd") ; +#endif /* NDEBUG */ + + /* === Check the input arguments ======================================== */ + + if (!stats) + { + DEBUG0 (("symamd: stats not present\n")) ; + return (FALSE) ; + } + for (i = 0 ; i < COLAMD_STATS ; i++) + { + stats [i] = 0 ; + } + stats [COLAMD_STATUS] = COLAMD_OK ; + stats [COLAMD_INFO1] = -1 ; + stats [COLAMD_INFO2] = -1 ; + + if (!A) + { + stats [COLAMD_STATUS] = COLAMD_ERROR_A_not_present ; + DEBUG0 (("symamd: A not present\n")) ; + return (FALSE) ; + } + + if (!p) /* p is not present */ + { + stats [COLAMD_STATUS] = COLAMD_ERROR_p_not_present ; + DEBUG0 (("symamd: p not present\n")) ; + return (FALSE) ; + } + + if (n < 0) /* n must be >= 0 */ + { + stats [COLAMD_STATUS] = COLAMD_ERROR_ncol_negative ; + stats [COLAMD_INFO1] = n ; + DEBUG0 (("symamd: n negative %d\n", n)) ; + return (FALSE) ; + } + + nnz = p [n] ; + if (nnz < 0) /* nnz must be >= 0 */ + { + stats [COLAMD_STATUS] = COLAMD_ERROR_nnz_negative ; + stats [COLAMD_INFO1] = nnz ; + DEBUG0 (("symamd: number of entries negative %d\n", nnz)) ; + return (FALSE) ; + } + + if (p [0] != 0) + { + stats [COLAMD_STATUS] = COLAMD_ERROR_p0_nonzero ; + stats [COLAMD_INFO1] = p [0] ; + DEBUG0 (("symamd: p[0] not zero %d\n", p [0])) ; + return (FALSE) ; + } + + /* === If no knobs, set default knobs =================================== */ + + if (!knobs) + { + COLAMD_set_defaults (default_knobs) ; + knobs = default_knobs ; + } + + /* === Allocate count and mark ========================================== */ + + count = (Int *) ((*allocate) (n+1, sizeof (Int))) ; + if (!count) + { + stats [COLAMD_STATUS] = COLAMD_ERROR_out_of_memory ; + DEBUG0 (("symamd: allocate count (size %d) failed\n", n+1)) ; + return (FALSE) ; + } + + mark = (Int *) ((*allocate) (n+1, sizeof (Int))) ; + if (!mark) + { + stats [COLAMD_STATUS] = COLAMD_ERROR_out_of_memory ; + (*release) ((void *) count) ; + DEBUG0 (("symamd: allocate mark (size %d) failed\n", n+1)) ; + return (FALSE) ; + } + + /* === Compute column counts of M, check if A is valid ================== */ + + stats [COLAMD_INFO3] = 0 ; /* number of duplicate or unsorted row indices*/ + + for (i = 0 ; i < n ; i++) + { + mark [i] = -1 ; + } + + for (j = 0 ; j < n ; j++) + { + last_row = -1 ; + + length = p [j+1] - p [j] ; + if (length < 0) + { + /* column pointers must be non-decreasing */ + stats [COLAMD_STATUS] = COLAMD_ERROR_col_length_negative ; + stats [COLAMD_INFO1] = j ; + stats [COLAMD_INFO2] = length ; + (*release) ((void *) count) ; + (*release) ((void *) mark) ; + DEBUG0 (("symamd: col %d negative length %d\n", j, length)) ; + return (FALSE) ; + } + + for (pp = p [j] ; pp < p [j+1] ; pp++) + { + i = A [pp] ; + if (i < 0 || i >= n) + { + /* row index i, in column j, is out of bounds */ + stats [COLAMD_STATUS] = COLAMD_ERROR_row_index_out_of_bounds ; + stats [COLAMD_INFO1] = j ; + stats [COLAMD_INFO2] = i ; + stats [COLAMD_INFO3] = n ; + (*release) ((void *) count) ; + (*release) ((void *) mark) ; + DEBUG0 (("symamd: row %d col %d out of bounds\n", i, j)) ; + return (FALSE) ; + } + + if (i <= last_row || mark [i] == j) + { + /* row index is unsorted or repeated (or both), thus col */ + /* is jumbled. This is a notice, not an error condition. */ + stats [COLAMD_STATUS] = COLAMD_OK_BUT_JUMBLED ; + stats [COLAMD_INFO1] = j ; + stats [COLAMD_INFO2] = i ; + (stats [COLAMD_INFO3]) ++ ; + DEBUG1 (("symamd: row %d col %d unsorted/duplicate\n", i, j)) ; + } + + if (i > j && mark [i] != j) + { + /* row k of M will contain column indices i and j */ + count [i]++ ; + count [j]++ ; + } + + /* mark the row as having been seen in this column */ + mark [i] = j ; + + last_row = i ; + } + } + + /* v2.4: removed free(mark) */ + + /* === Compute column pointers of M ===================================== */ + + /* use output permutation, perm, for column pointers of M */ + perm [0] = 0 ; + for (j = 1 ; j <= n ; j++) + { + perm [j] = perm [j-1] + count [j-1] ; + } + for (j = 0 ; j < n ; j++) + { + count [j] = perm [j] ; + } + + /* === Construct M ====================================================== */ + + mnz = perm [n] ; + n_row = mnz / 2 ; + Mlen = COLAMD_recommended (mnz, n_row, n) ; + M = (Int *) ((*allocate) (Mlen, sizeof (Int))) ; + DEBUG0 (("symamd: M is %d-by-%d with %d entries, Mlen = %g\n", + n_row, n, mnz, (double) Mlen)) ; + + if (!M) + { + stats [COLAMD_STATUS] = COLAMD_ERROR_out_of_memory ; + (*release) ((void *) count) ; + (*release) ((void *) mark) ; + DEBUG0 (("symamd: allocate M (size %g) failed\n", (double) Mlen)) ; + return (FALSE) ; + } + + k = 0 ; + + if (stats [COLAMD_STATUS] == COLAMD_OK) + { + /* Matrix is OK */ + for (j = 0 ; j < n ; j++) + { + ASSERT (p [j+1] - p [j] >= 0) ; + for (pp = p [j] ; pp < p [j+1] ; pp++) + { + i = A [pp] ; + ASSERT (i >= 0 && i < n) ; + if (i > j) + { + /* row k of M contains column indices i and j */ + M [count [i]++] = k ; + M [count [j]++] = k ; + k++ ; + } + } + } + } + else + { + /* Matrix is jumbled. Do not add duplicates to M. Unsorted cols OK. */ + DEBUG0 (("symamd: Duplicates in A.\n")) ; + for (i = 0 ; i < n ; i++) + { + mark [i] = -1 ; + } + for (j = 0 ; j < n ; j++) + { + ASSERT (p [j+1] - p [j] >= 0) ; + for (pp = p [j] ; pp < p [j+1] ; pp++) + { + i = A [pp] ; + ASSERT (i >= 0 && i < n) ; + if (i > j && mark [i] != j) + { + /* row k of M contains column indices i and j */ + M [count [i]++] = k ; + M [count [j]++] = k ; + k++ ; + mark [i] = j ; + } + } + } + /* v2.4: free(mark) moved below */ + } + + /* count and mark no longer needed */ + (*release) ((void *) count) ; + (*release) ((void *) mark) ; /* v2.4: free (mark) moved here */ + ASSERT (k == n_row) ; + + /* === Adjust the knobs for M =========================================== */ + + for (i = 0 ; i < COLAMD_KNOBS ; i++) + { + cknobs [i] = knobs [i] ; + } + + /* there are no dense rows in M */ + cknobs [COLAMD_DENSE_ROW] = -1 ; + cknobs [COLAMD_DENSE_COL] = knobs [COLAMD_DENSE_ROW] ; + + /* === Order the columns of M =========================================== */ + + /* v2.4: colamd cannot fail here, so the error check is removed */ + (void) COLAMD_MAIN (n_row, n, (Int) Mlen, M, perm, cknobs, stats) ; + + /* Note that the output permutation is now in perm */ + + /* === get the statistics for symamd from colamd ======================== */ + + /* a dense column in colamd means a dense row and col in symamd */ + stats [COLAMD_DENSE_ROW] = stats [COLAMD_DENSE_COL] ; + + /* === Free M =========================================================== */ + + (*release) ((void *) M) ; + DEBUG0 (("symamd: done.\n")) ; + return (TRUE) ; + +} + +/* ========================================================================== */ +/* === colamd =============================================================== */ +/* ========================================================================== */ + +/* + The colamd routine computes a column ordering Q of a sparse matrix + A such that the LU factorization P(AQ) = LU remains sparse, where P is + selected via partial pivoting. The routine can also be viewed as + providing a permutation Q such that the Cholesky factorization + (AQ)'(AQ) = LL' remains sparse. +*/ + +PUBLIC Int COLAMD_MAIN /* returns TRUE if successful, FALSE otherwise*/ +( + /* === Parameters ======================================================= */ + + Int n_row, /* number of rows in A */ + Int n_col, /* number of columns in A */ + Int Alen, /* length of A */ + Int A [], /* row indices of A */ + Int p [], /* pointers to columns in A */ + double knobs [COLAMD_KNOBS],/* parameters (uses defaults if NULL) */ + Int stats [COLAMD_STATS] /* output statistics and error codes */ +) +{ + /* === Local variables ================================================== */ + + Int i ; /* loop index */ + Int nnz ; /* nonzeros in A */ + size_t Row_size ; /* size of Row [], in integers */ + size_t Col_size ; /* size of Col [], in integers */ + size_t need ; /* minimum required length of A */ + Colamd_Row *Row ; /* pointer into A of Row [0..n_row] array */ + Colamd_Col *Col ; /* pointer into A of Col [0..n_col] array */ + Int n_col2 ; /* number of non-dense, non-empty columns */ + Int n_row2 ; /* number of non-dense, non-empty rows */ + Int ngarbage ; /* number of garbage collections performed */ + Int max_deg ; /* maximum row degree */ + double default_knobs [COLAMD_KNOBS] ; /* default knobs array */ + Int aggressive ; /* do aggressive absorption */ + int ok ; + +#ifndef NDEBUG + colamd_get_debug ("colamd") ; +#endif /* NDEBUG */ + + /* === Check the input arguments ======================================== */ + + if (!stats) + { + DEBUG0 (("colamd: stats not present\n")) ; + return (FALSE) ; + } + for (i = 0 ; i < COLAMD_STATS ; i++) + { + stats [i] = 0 ; + } + stats [COLAMD_STATUS] = COLAMD_OK ; + stats [COLAMD_INFO1] = -1 ; + stats [COLAMD_INFO2] = -1 ; + + if (!A) /* A is not present */ + { + stats [COLAMD_STATUS] = COLAMD_ERROR_A_not_present ; + DEBUG0 (("colamd: A not present\n")) ; + return (FALSE) ; + } + + if (!p) /* p is not present */ + { + stats [COLAMD_STATUS] = COLAMD_ERROR_p_not_present ; + DEBUG0 (("colamd: p not present\n")) ; + return (FALSE) ; + } + + if (n_row < 0) /* n_row must be >= 0 */ + { + stats [COLAMD_STATUS] = COLAMD_ERROR_nrow_negative ; + stats [COLAMD_INFO1] = n_row ; + DEBUG0 (("colamd: nrow negative %d\n", n_row)) ; + return (FALSE) ; + } + + if (n_col < 0) /* n_col must be >= 0 */ + { + stats [COLAMD_STATUS] = COLAMD_ERROR_ncol_negative ; + stats [COLAMD_INFO1] = n_col ; + DEBUG0 (("colamd: ncol negative %d\n", n_col)) ; + return (FALSE) ; + } + + nnz = p [n_col] ; + if (nnz < 0) /* nnz must be >= 0 */ + { + stats [COLAMD_STATUS] = COLAMD_ERROR_nnz_negative ; + stats [COLAMD_INFO1] = nnz ; + DEBUG0 (("colamd: number of entries negative %d\n", nnz)) ; + return (FALSE) ; + } + + if (p [0] != 0) + { + stats [COLAMD_STATUS] = COLAMD_ERROR_p0_nonzero ; + stats [COLAMD_INFO1] = p [0] ; + DEBUG0 (("colamd: p[0] not zero %d\n", p [0])) ; + return (FALSE) ; + } + + /* === If no knobs, set default knobs =================================== */ + + if (!knobs) + { + COLAMD_set_defaults (default_knobs) ; + knobs = default_knobs ; + } + + aggressive = (knobs [COLAMD_AGGRESSIVE] != FALSE) ; + + /* === Allocate the Row and Col arrays from array A ===================== */ + + ok = TRUE ; + Col_size = COLAMD_C (n_col, &ok) ; /* size of Col array of structs */ + Row_size = COLAMD_R (n_row, &ok) ; /* size of Row array of structs */ + + /* need = 2*nnz + n_col + Col_size + Row_size ; */ + need = t_mult (nnz, 2, &ok) ; + need = t_add (need, n_col, &ok) ; + need = t_add (need, Col_size, &ok) ; + need = t_add (need, Row_size, &ok) ; + + if (!ok || need > (size_t) Alen || need > Int_MAX) + { + /* not enough space in array A to perform the ordering */ + stats [COLAMD_STATUS] = COLAMD_ERROR_A_too_small ; + stats [COLAMD_INFO1] = need ; + stats [COLAMD_INFO2] = Alen ; + DEBUG0 (("colamd: Need Alen >= %d, given only Alen = %d\n", need,Alen)); + return (FALSE) ; + } + + Alen -= Col_size + Row_size ; + Col = (Colamd_Col *) &A [Alen] ; + Row = (Colamd_Row *) &A [Alen + Col_size] ; + + /* === Construct the row and column data structures ===================== */ + + if (!init_rows_cols (n_row, n_col, Row, Col, A, p, stats)) + { + /* input matrix is invalid */ + DEBUG0 (("colamd: Matrix invalid\n")) ; + return (FALSE) ; + } + + /* === Initialize scores, kill dense rows/columns ======================= */ + + init_scoring (n_row, n_col, Row, Col, A, p, knobs, + &n_row2, &n_col2, &max_deg) ; + + /* === Order the supercolumns =========================================== */ + + ngarbage = find_ordering (n_row, n_col, Alen, Row, Col, A, p, + n_col2, max_deg, 2*nnz, aggressive) ; + + /* === Order the non-principal columns ================================== */ + + order_children (n_col, Col, p) ; + + /* === Return statistics in stats ======================================= */ + + stats [COLAMD_DENSE_ROW] = n_row - n_row2 ; + stats [COLAMD_DENSE_COL] = n_col - n_col2 ; + stats [COLAMD_DEFRAG_COUNT] = ngarbage ; + DEBUG0 (("colamd: done.\n")) ; + return (TRUE) ; +} + + +/* ========================================================================== */ +/* === colamd_report ======================================================== */ +/* ========================================================================== */ + +PUBLIC void COLAMD_report +( + Int stats [COLAMD_STATS] +) +{ + print_report ("colamd", stats) ; +} + + +/* ========================================================================== */ +/* === symamd_report ======================================================== */ +/* ========================================================================== */ + +PUBLIC void SYMAMD_report +( + Int stats [COLAMD_STATS] +) +{ + print_report ("symamd", stats) ; +} + + + +/* ========================================================================== */ +/* === NON-USER-CALLABLE ROUTINES: ========================================== */ +/* ========================================================================== */ + +/* There are no user-callable routines beyond this point in the file */ + + +/* ========================================================================== */ +/* === init_rows_cols ======================================================= */ +/* ========================================================================== */ + +/* + Takes the column form of the matrix in A and creates the row form of the + matrix. Also, row and column attributes are stored in the Col and Row + structs. If the columns are un-sorted or contain duplicate row indices, + this routine will also sort and remove duplicate row indices from the + column form of the matrix. Returns FALSE if the matrix is invalid, + TRUE otherwise. Not user-callable. +*/ + +PRIVATE Int init_rows_cols /* returns TRUE if OK, or FALSE otherwise */ +( + /* === Parameters ======================================================= */ + + Int n_row, /* number of rows of A */ + Int n_col, /* number of columns of A */ + Colamd_Row Row [], /* of size n_row+1 */ + Colamd_Col Col [], /* of size n_col+1 */ + Int A [], /* row indices of A, of size Alen */ + Int p [], /* pointers to columns in A, of size n_col+1 */ + Int stats [COLAMD_STATS] /* colamd statistics */ +) +{ + /* === Local variables ================================================== */ + + Int col ; /* a column index */ + Int row ; /* a row index */ + Int *cp ; /* a column pointer */ + Int *cp_end ; /* a pointer to the end of a column */ + Int *rp ; /* a row pointer */ + Int *rp_end ; /* a pointer to the end of a row */ + Int last_row ; /* previous row */ + + /* === Initialize columns, and check column pointers ==================== */ + + for (col = 0 ; col < n_col ; col++) + { + Col [col].start = p [col] ; + Col [col].length = p [col+1] - p [col] ; + + if (Col [col].length < 0) + { + /* column pointers must be non-decreasing */ + stats [COLAMD_STATUS] = COLAMD_ERROR_col_length_negative ; + stats [COLAMD_INFO1] = col ; + stats [COLAMD_INFO2] = Col [col].length ; + DEBUG0 (("colamd: col %d length %d < 0\n", col, Col [col].length)) ; + return (FALSE) ; + } + + Col [col].shared1.thickness = 1 ; + Col [col].shared2.score = 0 ; + Col [col].shared3.prev = EMPTY ; + Col [col].shared4.degree_next = EMPTY ; + } + + /* p [0..n_col] no longer needed, used as "head" in subsequent routines */ + + /* === Scan columns, compute row degrees, and check row indices ========= */ + + stats [COLAMD_INFO3] = 0 ; /* number of duplicate or unsorted row indices*/ + + for (row = 0 ; row < n_row ; row++) + { + Row [row].length = 0 ; + Row [row].shared2.mark = -1 ; + } + + for (col = 0 ; col < n_col ; col++) + { + last_row = -1 ; + + cp = &A [p [col]] ; + cp_end = &A [p [col+1]] ; + + while (cp < cp_end) + { + row = *cp++ ; + + /* make sure row indices within range */ + if (row < 0 || row >= n_row) + { + stats [COLAMD_STATUS] = COLAMD_ERROR_row_index_out_of_bounds ; + stats [COLAMD_INFO1] = col ; + stats [COLAMD_INFO2] = row ; + stats [COLAMD_INFO3] = n_row ; + DEBUG0 (("colamd: row %d col %d out of bounds\n", row, col)) ; + return (FALSE) ; + } + + if (row <= last_row || Row [row].shared2.mark == col) + { + /* row index are unsorted or repeated (or both), thus col */ + /* is jumbled. This is a notice, not an error condition. */ + stats [COLAMD_STATUS] = COLAMD_OK_BUT_JUMBLED ; + stats [COLAMD_INFO1] = col ; + stats [COLAMD_INFO2] = row ; + (stats [COLAMD_INFO3]) ++ ; + DEBUG1 (("colamd: row %d col %d unsorted/duplicate\n",row,col)); + } + + if (Row [row].shared2.mark != col) + { + Row [row].length++ ; + } + else + { + /* this is a repeated entry in the column, */ + /* it will be removed */ + Col [col].length-- ; + } + + /* mark the row as having been seen in this column */ + Row [row].shared2.mark = col ; + + last_row = row ; + } + } + + /* === Compute row pointers ============================================= */ + + /* row form of the matrix starts directly after the column */ + /* form of matrix in A */ + Row [0].start = p [n_col] ; + Row [0].shared1.p = Row [0].start ; + Row [0].shared2.mark = -1 ; + for (row = 1 ; row < n_row ; row++) + { + Row [row].start = Row [row-1].start + Row [row-1].length ; + Row [row].shared1.p = Row [row].start ; + Row [row].shared2.mark = -1 ; + } + + /* === Create row form ================================================== */ + + if (stats [COLAMD_STATUS] == COLAMD_OK_BUT_JUMBLED) + { + /* if cols jumbled, watch for repeated row indices */ + for (col = 0 ; col < n_col ; col++) + { + cp = &A [p [col]] ; + cp_end = &A [p [col+1]] ; + while (cp < cp_end) + { + row = *cp++ ; + if (Row [row].shared2.mark != col) + { + A [(Row [row].shared1.p)++] = col ; + Row [row].shared2.mark = col ; + } + } + } + } + else + { + /* if cols not jumbled, we don't need the mark (this is faster) */ + for (col = 0 ; col < n_col ; col++) + { + cp = &A [p [col]] ; + cp_end = &A [p [col+1]] ; + while (cp < cp_end) + { + A [(Row [*cp++].shared1.p)++] = col ; + } + } + } + + /* === Clear the row marks and set row degrees ========================== */ + + for (row = 0 ; row < n_row ; row++) + { + Row [row].shared2.mark = 0 ; + Row [row].shared1.degree = Row [row].length ; + } + + /* === See if we need to re-create columns ============================== */ + + if (stats [COLAMD_STATUS] == COLAMD_OK_BUT_JUMBLED) + { + DEBUG0 (("colamd: reconstructing column form, matrix jumbled\n")) ; + +#ifndef NDEBUG + /* make sure column lengths are correct */ + for (col = 0 ; col < n_col ; col++) + { + p [col] = Col [col].length ; + } + for (row = 0 ; row < n_row ; row++) + { + rp = &A [Row [row].start] ; + rp_end = rp + Row [row].length ; + while (rp < rp_end) + { + p [*rp++]-- ; + } + } + for (col = 0 ; col < n_col ; col++) + { + ASSERT (p [col] == 0) ; + } + /* now p is all zero (different than when debugging is turned off) */ +#endif /* NDEBUG */ + + /* === Compute col pointers ========================================= */ + + /* col form of the matrix starts at A [0]. */ + /* Note, we may have a gap between the col form and the row */ + /* form if there were duplicate entries, if so, it will be */ + /* removed upon the first garbage collection */ + Col [0].start = 0 ; + p [0] = Col [0].start ; + for (col = 1 ; col < n_col ; col++) + { + /* note that the lengths here are for pruned columns, i.e. */ + /* no duplicate row indices will exist for these columns */ + Col [col].start = Col [col-1].start + Col [col-1].length ; + p [col] = Col [col].start ; + } + + /* === Re-create col form =========================================== */ + + for (row = 0 ; row < n_row ; row++) + { + rp = &A [Row [row].start] ; + rp_end = rp + Row [row].length ; + while (rp < rp_end) + { + A [(p [*rp++])++] = row ; + } + } + } + + /* === Done. Matrix is not (or no longer) jumbled ====================== */ + + return (TRUE) ; +} + + +/* ========================================================================== */ +/* === init_scoring ========================================================= */ +/* ========================================================================== */ + +/* + Kills dense or empty columns and rows, calculates an initial score for + each column, and places all columns in the degree lists. Not user-callable. +*/ + +PRIVATE void init_scoring +( + /* === Parameters ======================================================= */ + + Int n_row, /* number of rows of A */ + Int n_col, /* number of columns of A */ + Colamd_Row Row [], /* of size n_row+1 */ + Colamd_Col Col [], /* of size n_col+1 */ + Int A [], /* column form and row form of A */ + Int head [], /* of size n_col+1 */ + double knobs [COLAMD_KNOBS],/* parameters */ + Int *p_n_row2, /* number of non-dense, non-empty rows */ + Int *p_n_col2, /* number of non-dense, non-empty columns */ + Int *p_max_deg /* maximum row degree */ +) +{ + /* === Local variables ================================================== */ + + Int c ; /* a column index */ + Int r, row ; /* a row index */ + Int *cp ; /* a column pointer */ + Int deg ; /* degree of a row or column */ + Int *cp_end ; /* a pointer to the end of a column */ + Int *new_cp ; /* new column pointer */ + Int col_length ; /* length of pruned column */ + Int score ; /* current column score */ + Int n_col2 ; /* number of non-dense, non-empty columns */ + Int n_row2 ; /* number of non-dense, non-empty rows */ + Int dense_row_count ; /* remove rows with more entries than this */ + Int dense_col_count ; /* remove cols with more entries than this */ + Int min_score ; /* smallest column score */ + Int max_deg ; /* maximum row degree */ + Int next_col ; /* Used to add to degree list.*/ + +#ifndef NDEBUG + Int debug_count ; /* debug only. */ +#endif /* NDEBUG */ + + /* === Extract knobs ==================================================== */ + + /* Note: if knobs contains a NaN, this is undefined: */ + if (knobs [COLAMD_DENSE_ROW] < 0) + { + /* only remove completely dense rows */ + dense_row_count = n_col-1 ; + } + else + { + dense_row_count = DENSE_DEGREE (knobs [COLAMD_DENSE_ROW], n_col) ; + } + if (knobs [COLAMD_DENSE_COL] < 0) + { + /* only remove completely dense columns */ + dense_col_count = n_row-1 ; + } + else + { + dense_col_count = + DENSE_DEGREE (knobs [COLAMD_DENSE_COL], MIN (n_row, n_col)) ; + } + + DEBUG1 (("colamd: densecount: %d %d\n", dense_row_count, dense_col_count)) ; + max_deg = 0 ; + n_col2 = n_col ; + n_row2 = n_row ; + + /* === Kill empty columns =============================================== */ + + /* Put the empty columns at the end in their natural order, so that LU */ + /* factorization can proceed as far as possible. */ + for (c = n_col-1 ; c >= 0 ; c--) + { + deg = Col [c].length ; + if (deg == 0) + { + /* this is a empty column, kill and order it last */ + Col [c].shared2.order = --n_col2 ; + KILL_PRINCIPAL_COL (c) ; + } + } + DEBUG1 (("colamd: null columns killed: %d\n", n_col - n_col2)) ; + + /* === Kill dense columns =============================================== */ + + /* Put the dense columns at the end, in their natural order */ + for (c = n_col-1 ; c >= 0 ; c--) + { + /* skip any dead columns */ + if (COL_IS_DEAD (c)) + { + continue ; + } + deg = Col [c].length ; + if (deg > dense_col_count) + { + /* this is a dense column, kill and order it last */ + Col [c].shared2.order = --n_col2 ; + /* decrement the row degrees */ + cp = &A [Col [c].start] ; + cp_end = cp + Col [c].length ; + while (cp < cp_end) + { + Row [*cp++].shared1.degree-- ; + } + KILL_PRINCIPAL_COL (c) ; + } + } + DEBUG1 (("colamd: Dense and null columns killed: %d\n", n_col - n_col2)) ; + + /* === Kill dense and empty rows ======================================== */ + + for (r = 0 ; r < n_row ; r++) + { + deg = Row [r].shared1.degree ; + ASSERT (deg >= 0 && deg <= n_col) ; + if (deg > dense_row_count || deg == 0) + { + /* kill a dense or empty row */ + KILL_ROW (r) ; + --n_row2 ; + } + else + { + /* keep track of max degree of remaining rows */ + max_deg = MAX (max_deg, deg) ; + } + } + DEBUG1 (("colamd: Dense and null rows killed: %d\n", n_row - n_row2)) ; + + /* === Compute initial column scores ==================================== */ + + /* At this point the row degrees are accurate. They reflect the number */ + /* of "live" (non-dense) columns in each row. No empty rows exist. */ + /* Some "live" columns may contain only dead rows, however. These are */ + /* pruned in the code below. */ + + /* now find the initial matlab score for each column */ + for (c = n_col-1 ; c >= 0 ; c--) + { + /* skip dead column */ + if (COL_IS_DEAD (c)) + { + continue ; + } + score = 0 ; + cp = &A [Col [c].start] ; + new_cp = cp ; + cp_end = cp + Col [c].length ; + while (cp < cp_end) + { + /* get a row */ + row = *cp++ ; + /* skip if dead */ + if (ROW_IS_DEAD (row)) + { + continue ; + } + /* compact the column */ + *new_cp++ = row ; + /* add row's external degree */ + score += Row [row].shared1.degree - 1 ; + /* guard against integer overflow */ + score = MIN (score, n_col) ; + } + /* determine pruned column length */ + col_length = (Int) (new_cp - &A [Col [c].start]) ; + if (col_length == 0) + { + /* a newly-made null column (all rows in this col are "dense" */ + /* and have already been killed) */ + DEBUG2 (("Newly null killed: %d\n", c)) ; + Col [c].shared2.order = --n_col2 ; + KILL_PRINCIPAL_COL (c) ; + } + else + { + /* set column length and set score */ + ASSERT (score >= 0) ; + ASSERT (score <= n_col) ; + Col [c].length = col_length ; + Col [c].shared2.score = score ; + } + } + DEBUG1 (("colamd: Dense, null, and newly-null columns killed: %d\n", + n_col-n_col2)) ; + + /* At this point, all empty rows and columns are dead. All live columns */ + /* are "clean" (containing no dead rows) and simplicial (no supercolumns */ + /* yet). Rows may contain dead columns, but all live rows contain at */ + /* least one live column. */ + +#ifndef NDEBUG + debug_structures (n_row, n_col, Row, Col, A, n_col2) ; +#endif /* NDEBUG */ + + /* === Initialize degree lists ========================================== */ + +#ifndef NDEBUG + debug_count = 0 ; +#endif /* NDEBUG */ + + /* clear the hash buckets */ + for (c = 0 ; c <= n_col ; c++) + { + head [c] = EMPTY ; + } + min_score = n_col ; + /* place in reverse order, so low column indices are at the front */ + /* of the lists. This is to encourage natural tie-breaking */ + for (c = n_col-1 ; c >= 0 ; c--) + { + /* only add principal columns to degree lists */ + if (COL_IS_ALIVE (c)) + { + DEBUG4 (("place %d score %d minscore %d ncol %d\n", + c, Col [c].shared2.score, min_score, n_col)) ; + + /* === Add columns score to DList =============================== */ + + score = Col [c].shared2.score ; + + ASSERT (min_score >= 0) ; + ASSERT (min_score <= n_col) ; + ASSERT (score >= 0) ; + ASSERT (score <= n_col) ; + ASSERT (head [score] >= EMPTY) ; + + /* now add this column to dList at proper score location */ + next_col = head [score] ; + Col [c].shared3.prev = EMPTY ; + Col [c].shared4.degree_next = next_col ; + + /* if there already was a column with the same score, set its */ + /* previous pointer to this new column */ + if (next_col != EMPTY) + { + Col [next_col].shared3.prev = c ; + } + head [score] = c ; + + /* see if this score is less than current min */ + min_score = MIN (min_score, score) ; + +#ifndef NDEBUG + debug_count++ ; +#endif /* NDEBUG */ + + } + } + +#ifndef NDEBUG + DEBUG1 (("colamd: Live cols %d out of %d, non-princ: %d\n", + debug_count, n_col, n_col-debug_count)) ; + ASSERT (debug_count == n_col2) ; + debug_deg_lists (n_row, n_col, Row, Col, head, min_score, n_col2, max_deg) ; +#endif /* NDEBUG */ + + /* === Return number of remaining columns, and max row degree =========== */ + + *p_n_col2 = n_col2 ; + *p_n_row2 = n_row2 ; + *p_max_deg = max_deg ; +} + + +/* ========================================================================== */ +/* === find_ordering ======================================================== */ +/* ========================================================================== */ + +/* + Order the principal columns of the supercolumn form of the matrix + (no supercolumns on input). Uses a minimum approximate column minimum + degree ordering method. Not user-callable. +*/ + +PRIVATE Int find_ordering /* return the number of garbage collections */ +( + /* === Parameters ======================================================= */ + + Int n_row, /* number of rows of A */ + Int n_col, /* number of columns of A */ + Int Alen, /* size of A, 2*nnz + n_col or larger */ + Colamd_Row Row [], /* of size n_row+1 */ + Colamd_Col Col [], /* of size n_col+1 */ + Int A [], /* column form and row form of A */ + Int head [], /* of size n_col+1 */ + Int n_col2, /* Remaining columns to order */ + Int max_deg, /* Maximum row degree */ + Int pfree, /* index of first free slot (2*nnz on entry) */ + Int aggressive +) +{ + /* === Local variables ================================================== */ + + Int k ; /* current pivot ordering step */ + Int pivot_col ; /* current pivot column */ + Int *cp ; /* a column pointer */ + Int *rp ; /* a row pointer */ + Int pivot_row ; /* current pivot row */ + Int *new_cp ; /* modified column pointer */ + Int *new_rp ; /* modified row pointer */ + Int pivot_row_start ; /* pointer to start of pivot row */ + Int pivot_row_degree ; /* number of columns in pivot row */ + Int pivot_row_length ; /* number of supercolumns in pivot row */ + Int pivot_col_score ; /* score of pivot column */ + Int needed_memory ; /* free space needed for pivot row */ + Int *cp_end ; /* pointer to the end of a column */ + Int *rp_end ; /* pointer to the end of a row */ + Int row ; /* a row index */ + Int col ; /* a column index */ + Int max_score ; /* maximum possible score */ + Int cur_score ; /* score of current column */ + unsigned Int hash ; /* hash value for supernode detection */ + Int head_column ; /* head of hash bucket */ + Int first_col ; /* first column in hash bucket */ + Int tag_mark ; /* marker value for mark array */ + Int row_mark ; /* Row [row].shared2.mark */ + Int set_difference ; /* set difference size of row with pivot row */ + Int min_score ; /* smallest column score */ + Int col_thickness ; /* "thickness" (no. of columns in a supercol) */ + Int max_mark ; /* maximum value of tag_mark */ + Int pivot_col_thickness ; /* number of columns represented by pivot col */ + Int prev_col ; /* Used by Dlist operations. */ + Int next_col ; /* Used by Dlist operations. */ + Int ngarbage ; /* number of garbage collections performed */ + +#ifndef NDEBUG + Int debug_d ; /* debug loop counter */ + Int debug_step = 0 ; /* debug loop counter */ +#endif /* NDEBUG */ + + /* === Initialization and clear mark ==================================== */ + + max_mark = INT_MAX - n_col ; /* INT_MAX defined in */ + tag_mark = clear_mark (0, max_mark, n_row, Row) ; + min_score = 0 ; + ngarbage = 0 ; + DEBUG1 (("colamd: Ordering, n_col2=%d\n", n_col2)) ; + + /* === Order the columns ================================================ */ + + for (k = 0 ; k < n_col2 ; /* 'k' is incremented below */) + { + +#ifndef NDEBUG + if (debug_step % 100 == 0) + { + DEBUG2 (("\n... Step k: %d out of n_col2: %d\n", k, n_col2)) ; + } + else + { + DEBUG3 (("\n----------Step k: %d out of n_col2: %d\n", k, n_col2)) ; + } + debug_step++ ; + debug_deg_lists (n_row, n_col, Row, Col, head, + min_score, n_col2-k, max_deg) ; + debug_matrix (n_row, n_col, Row, Col, A) ; +#endif /* NDEBUG */ + + /* === Select pivot column, and order it ============================ */ + + /* make sure degree list isn't empty */ + ASSERT (min_score >= 0) ; + ASSERT (min_score <= n_col) ; + ASSERT (head [min_score] >= EMPTY) ; + +#ifndef NDEBUG + for (debug_d = 0 ; debug_d < min_score ; debug_d++) + { + ASSERT (head [debug_d] == EMPTY) ; + } +#endif /* NDEBUG */ + + /* get pivot column from head of minimum degree list */ + while (head [min_score] == EMPTY && min_score < n_col) + { + min_score++ ; + } + pivot_col = head [min_score] ; + ASSERT (pivot_col >= 0 && pivot_col <= n_col) ; + next_col = Col [pivot_col].shared4.degree_next ; + head [min_score] = next_col ; + if (next_col != EMPTY) + { + Col [next_col].shared3.prev = EMPTY ; + } + + ASSERT (COL_IS_ALIVE (pivot_col)) ; + + /* remember score for defrag check */ + pivot_col_score = Col [pivot_col].shared2.score ; + + /* the pivot column is the kth column in the pivot order */ + Col [pivot_col].shared2.order = k ; + + /* increment order count by column thickness */ + pivot_col_thickness = Col [pivot_col].shared1.thickness ; + k += pivot_col_thickness ; + ASSERT (pivot_col_thickness > 0) ; + DEBUG3 (("Pivot col: %d thick %d\n", pivot_col, pivot_col_thickness)) ; + + /* === Garbage_collection, if necessary ============================= */ + + needed_memory = MIN (pivot_col_score, n_col - k) ; + if (pfree + needed_memory >= Alen) + { + pfree = garbage_collection (n_row, n_col, Row, Col, A, &A [pfree]) ; + ngarbage++ ; + /* after garbage collection we will have enough */ + ASSERT (pfree + needed_memory < Alen) ; + /* garbage collection has wiped out the Row[].shared2.mark array */ + tag_mark = clear_mark (0, max_mark, n_row, Row) ; + +#ifndef NDEBUG + debug_matrix (n_row, n_col, Row, Col, A) ; +#endif /* NDEBUG */ + } + + /* === Compute pivot row pattern ==================================== */ + + /* get starting location for this new merged row */ + pivot_row_start = pfree ; + + /* initialize new row counts to zero */ + pivot_row_degree = 0 ; + + /* tag pivot column as having been visited so it isn't included */ + /* in merged pivot row */ + Col [pivot_col].shared1.thickness = -pivot_col_thickness ; + + /* pivot row is the union of all rows in the pivot column pattern */ + cp = &A [Col [pivot_col].start] ; + cp_end = cp + Col [pivot_col].length ; + while (cp < cp_end) + { + /* get a row */ + row = *cp++ ; + DEBUG4 (("Pivot col pattern %d %d\n", ROW_IS_ALIVE (row), row)) ; + /* skip if row is dead */ + if (ROW_IS_ALIVE (row)) + { + rp = &A [Row [row].start] ; + rp_end = rp + Row [row].length ; + while (rp < rp_end) + { + /* get a column */ + col = *rp++ ; + /* add the column, if alive and untagged */ + col_thickness = Col [col].shared1.thickness ; + if (col_thickness > 0 && COL_IS_ALIVE (col)) + { + /* tag column in pivot row */ + Col [col].shared1.thickness = -col_thickness ; + ASSERT (pfree < Alen) ; + /* place column in pivot row */ + A [pfree++] = col ; + pivot_row_degree += col_thickness ; + } + } + } + } + + /* clear tag on pivot column */ + Col [pivot_col].shared1.thickness = pivot_col_thickness ; + max_deg = MAX (max_deg, pivot_row_degree) ; + +#ifndef NDEBUG + DEBUG3 (("check2\n")) ; + debug_mark (n_row, Row, tag_mark, max_mark) ; +#endif /* NDEBUG */ + + /* === Kill all rows used to construct pivot row ==================== */ + + /* also kill pivot row, temporarily */ + cp = &A [Col [pivot_col].start] ; + cp_end = cp + Col [pivot_col].length ; + while (cp < cp_end) + { + /* may be killing an already dead row */ + row = *cp++ ; + DEBUG3 (("Kill row in pivot col: %d\n", row)) ; + KILL_ROW (row) ; + } + + /* === Select a row index to use as the new pivot row =============== */ + + pivot_row_length = pfree - pivot_row_start ; + if (pivot_row_length > 0) + { + /* pick the "pivot" row arbitrarily (first row in col) */ + pivot_row = A [Col [pivot_col].start] ; + DEBUG3 (("Pivotal row is %d\n", pivot_row)) ; + } + else + { + /* there is no pivot row, since it is of zero length */ + pivot_row = EMPTY ; + ASSERT (pivot_row_length == 0) ; + } + ASSERT (Col [pivot_col].length > 0 || pivot_row_length == 0) ; + + /* === Approximate degree computation =============================== */ + + /* Here begins the computation of the approximate degree. The column */ + /* score is the sum of the pivot row "length", plus the size of the */ + /* set differences of each row in the column minus the pattern of the */ + /* pivot row itself. The column ("thickness") itself is also */ + /* excluded from the column score (we thus use an approximate */ + /* external degree). */ + + /* The time taken by the following code (compute set differences, and */ + /* add them up) is proportional to the size of the data structure */ + /* being scanned - that is, the sum of the sizes of each column in */ + /* the pivot row. Thus, the amortized time to compute a column score */ + /* is proportional to the size of that column (where size, in this */ + /* context, is the column "length", or the number of row indices */ + /* in that column). The number of row indices in a column is */ + /* monotonically non-decreasing, from the length of the original */ + /* column on input to colamd. */ + + /* === Compute set differences ====================================== */ + + DEBUG3 (("** Computing set differences phase. **\n")) ; + + /* pivot row is currently dead - it will be revived later. */ + + DEBUG3 (("Pivot row: ")) ; + /* for each column in pivot row */ + rp = &A [pivot_row_start] ; + rp_end = rp + pivot_row_length ; + while (rp < rp_end) + { + col = *rp++ ; + ASSERT (COL_IS_ALIVE (col) && col != pivot_col) ; + DEBUG3 (("Col: %d\n", col)) ; + + /* clear tags used to construct pivot row pattern */ + col_thickness = -Col [col].shared1.thickness ; + ASSERT (col_thickness > 0) ; + Col [col].shared1.thickness = col_thickness ; + + /* === Remove column from degree list =========================== */ + + cur_score = Col [col].shared2.score ; + prev_col = Col [col].shared3.prev ; + next_col = Col [col].shared4.degree_next ; + ASSERT (cur_score >= 0) ; + ASSERT (cur_score <= n_col) ; + ASSERT (cur_score >= EMPTY) ; + if (prev_col == EMPTY) + { + head [cur_score] = next_col ; + } + else + { + Col [prev_col].shared4.degree_next = next_col ; + } + if (next_col != EMPTY) + { + Col [next_col].shared3.prev = prev_col ; + } + + /* === Scan the column ========================================== */ + + cp = &A [Col [col].start] ; + cp_end = cp + Col [col].length ; + while (cp < cp_end) + { + /* get a row */ + row = *cp++ ; + row_mark = Row [row].shared2.mark ; + /* skip if dead */ + if (ROW_IS_MARKED_DEAD (row_mark)) + { + continue ; + } + ASSERT (row != pivot_row) ; + set_difference = row_mark - tag_mark ; + /* check if the row has been seen yet */ + if (set_difference < 0) + { + ASSERT (Row [row].shared1.degree <= max_deg) ; + set_difference = Row [row].shared1.degree ; + } + /* subtract column thickness from this row's set difference */ + set_difference -= col_thickness ; + ASSERT (set_difference >= 0) ; + /* absorb this row if the set difference becomes zero */ + if (set_difference == 0 && aggressive) + { + DEBUG3 (("aggressive absorption. Row: %d\n", row)) ; + KILL_ROW (row) ; + } + else + { + /* save the new mark */ + Row [row].shared2.mark = set_difference + tag_mark ; + } + } + } + +#ifndef NDEBUG + debug_deg_lists (n_row, n_col, Row, Col, head, + min_score, n_col2-k-pivot_row_degree, max_deg) ; +#endif /* NDEBUG */ + + /* === Add up set differences for each column ======================= */ + + DEBUG3 (("** Adding set differences phase. **\n")) ; + + /* for each column in pivot row */ + rp = &A [pivot_row_start] ; + rp_end = rp + pivot_row_length ; + while (rp < rp_end) + { + /* get a column */ + col = *rp++ ; + ASSERT (COL_IS_ALIVE (col) && col != pivot_col) ; + hash = 0 ; + cur_score = 0 ; + cp = &A [Col [col].start] ; + /* compact the column */ + new_cp = cp ; + cp_end = cp + Col [col].length ; + + DEBUG4 (("Adding set diffs for Col: %d.\n", col)) ; + + while (cp < cp_end) + { + /* get a row */ + row = *cp++ ; + ASSERT(row >= 0 && row < n_row) ; + row_mark = Row [row].shared2.mark ; + /* skip if dead */ + if (ROW_IS_MARKED_DEAD (row_mark)) + { + DEBUG4 ((" Row %d, dead\n", row)) ; + continue ; + } + DEBUG4 ((" Row %d, set diff %d\n", row, row_mark-tag_mark)); + ASSERT (row_mark >= tag_mark) ; + /* compact the column */ + *new_cp++ = row ; + /* compute hash function */ + hash += row ; + /* add set difference */ + cur_score += row_mark - tag_mark ; + /* integer overflow... */ + cur_score = MIN (cur_score, n_col) ; + } + + /* recompute the column's length */ + Col [col].length = (Int) (new_cp - &A [Col [col].start]) ; + + /* === Further mass elimination ================================= */ + + if (Col [col].length == 0) + { + DEBUG4 (("further mass elimination. Col: %d\n", col)) ; + /* nothing left but the pivot row in this column */ + KILL_PRINCIPAL_COL (col) ; + pivot_row_degree -= Col [col].shared1.thickness ; + ASSERT (pivot_row_degree >= 0) ; + /* order it */ + Col [col].shared2.order = k ; + /* increment order count by column thickness */ + k += Col [col].shared1.thickness ; + } + else + { + /* === Prepare for supercolumn detection ==================== */ + + DEBUG4 (("Preparing supercol detection for Col: %d.\n", col)) ; + + /* save score so far */ + Col [col].shared2.score = cur_score ; + + /* add column to hash table, for supercolumn detection */ + hash %= n_col + 1 ; + + DEBUG4 ((" Hash = %d, n_col = %d.\n", hash, n_col)) ; + ASSERT (((Int) hash) <= n_col) ; + + head_column = head [hash] ; + if (head_column > EMPTY) + { + /* degree list "hash" is non-empty, use prev (shared3) of */ + /* first column in degree list as head of hash bucket */ + first_col = Col [head_column].shared3.headhash ; + Col [head_column].shared3.headhash = col ; + } + else + { + /* degree list "hash" is empty, use head as hash bucket */ + first_col = - (head_column + 2) ; + head [hash] = - (col + 2) ; + } + Col [col].shared4.hash_next = first_col ; + + /* save hash function in Col [col].shared3.hash */ + Col [col].shared3.hash = (Int) hash ; + ASSERT (COL_IS_ALIVE (col)) ; + } + } + + /* The approximate external column degree is now computed. */ + + /* === Supercolumn detection ======================================== */ + + DEBUG3 (("** Supercolumn detection phase. **\n")) ; + + detect_super_cols ( + +#ifndef NDEBUG + n_col, Row, +#endif /* NDEBUG */ + + Col, A, head, pivot_row_start, pivot_row_length) ; + + /* === Kill the pivotal column ====================================== */ + + KILL_PRINCIPAL_COL (pivot_col) ; + + /* === Clear mark =================================================== */ + + tag_mark = clear_mark (tag_mark+max_deg+1, max_mark, n_row, Row) ; + +#ifndef NDEBUG + DEBUG3 (("check3\n")) ; + debug_mark (n_row, Row, tag_mark, max_mark) ; +#endif /* NDEBUG */ + + /* === Finalize the new pivot row, and column scores ================ */ + + DEBUG3 (("** Finalize scores phase. **\n")) ; + + /* for each column in pivot row */ + rp = &A [pivot_row_start] ; + /* compact the pivot row */ + new_rp = rp ; + rp_end = rp + pivot_row_length ; + while (rp < rp_end) + { + col = *rp++ ; + /* skip dead columns */ + if (COL_IS_DEAD (col)) + { + continue ; + } + *new_rp++ = col ; + /* add new pivot row to column */ + A [Col [col].start + (Col [col].length++)] = pivot_row ; + + /* retrieve score so far and add on pivot row's degree. */ + /* (we wait until here for this in case the pivot */ + /* row's degree was reduced due to mass elimination). */ + cur_score = Col [col].shared2.score + pivot_row_degree ; + + /* calculate the max possible score as the number of */ + /* external columns minus the 'k' value minus the */ + /* columns thickness */ + max_score = n_col - k - Col [col].shared1.thickness ; + + /* make the score the external degree of the union-of-rows */ + cur_score -= Col [col].shared1.thickness ; + + /* make sure score is less or equal than the max score */ + cur_score = MIN (cur_score, max_score) ; + ASSERT (cur_score >= 0) ; + + /* store updated score */ + Col [col].shared2.score = cur_score ; + + /* === Place column back in degree list ========================= */ + + ASSERT (min_score >= 0) ; + ASSERT (min_score <= n_col) ; + ASSERT (cur_score >= 0) ; + ASSERT (cur_score <= n_col) ; + ASSERT (head [cur_score] >= EMPTY) ; + next_col = head [cur_score] ; + Col [col].shared4.degree_next = next_col ; + Col [col].shared3.prev = EMPTY ; + if (next_col != EMPTY) + { + Col [next_col].shared3.prev = col ; + } + head [cur_score] = col ; + + /* see if this score is less than current min */ + min_score = MIN (min_score, cur_score) ; + + } + +#ifndef NDEBUG + debug_deg_lists (n_row, n_col, Row, Col, head, + min_score, n_col2-k, max_deg) ; +#endif /* NDEBUG */ + + /* === Resurrect the new pivot row ================================== */ + + if (pivot_row_degree > 0) + { + /* update pivot row length to reflect any cols that were killed */ + /* during super-col detection and mass elimination */ + Row [pivot_row].start = pivot_row_start ; + Row [pivot_row].length = (Int) (new_rp - &A[pivot_row_start]) ; + ASSERT (Row [pivot_row].length > 0) ; + Row [pivot_row].shared1.degree = pivot_row_degree ; + Row [pivot_row].shared2.mark = 0 ; + /* pivot row is no longer dead */ + + DEBUG1 (("Resurrect Pivot_row %d deg: %d\n", + pivot_row, pivot_row_degree)) ; + } + } + + /* === All principal columns have now been ordered ====================== */ + + return (ngarbage) ; +} + + +/* ========================================================================== */ +/* === order_children ======================================================= */ +/* ========================================================================== */ + +/* + The find_ordering routine has ordered all of the principal columns (the + representatives of the supercolumns). The non-principal columns have not + yet been ordered. This routine orders those columns by walking up the + parent tree (a column is a child of the column which absorbed it). The + final permutation vector is then placed in p [0 ... n_col-1], with p [0] + being the first column, and p [n_col-1] being the last. It doesn't look + like it at first glance, but be assured that this routine takes time linear + in the number of columns. Although not immediately obvious, the time + taken by this routine is O (n_col), that is, linear in the number of + columns. Not user-callable. +*/ + +PRIVATE void order_children +( + /* === Parameters ======================================================= */ + + Int n_col, /* number of columns of A */ + Colamd_Col Col [], /* of size n_col+1 */ + Int p [] /* p [0 ... n_col-1] is the column permutation*/ +) +{ + /* === Local variables ================================================== */ + + Int i ; /* loop counter for all columns */ + Int c ; /* column index */ + Int parent ; /* index of column's parent */ + Int order ; /* column's order */ + + /* === Order each non-principal column ================================== */ + + for (i = 0 ; i < n_col ; i++) + { + /* find an un-ordered non-principal column */ + ASSERT (COL_IS_DEAD (i)) ; + if (!COL_IS_DEAD_PRINCIPAL (i) && Col [i].shared2.order == EMPTY) + { + parent = i ; + /* once found, find its principal parent */ + do + { + parent = Col [parent].shared1.parent ; + } while (!COL_IS_DEAD_PRINCIPAL (parent)) ; + + /* now, order all un-ordered non-principal columns along path */ + /* to this parent. collapse tree at the same time */ + c = i ; + /* get order of parent */ + order = Col [parent].shared2.order ; + + do + { + ASSERT (Col [c].shared2.order == EMPTY) ; + + /* order this column */ + Col [c].shared2.order = order++ ; + /* collaps tree */ + Col [c].shared1.parent = parent ; + + /* get immediate parent of this column */ + c = Col [c].shared1.parent ; + + /* continue until we hit an ordered column. There are */ + /* guarranteed not to be anymore unordered columns */ + /* above an ordered column */ + } while (Col [c].shared2.order == EMPTY) ; + + /* re-order the super_col parent to largest order for this group */ + Col [parent].shared2.order = order ; + } + } + + /* === Generate the permutation ========================================= */ + + for (c = 0 ; c < n_col ; c++) + { + p [Col [c].shared2.order] = c ; + } +} + + +/* ========================================================================== */ +/* === detect_super_cols ==================================================== */ +/* ========================================================================== */ + +/* + Detects supercolumns by finding matches between columns in the hash buckets. + Check amongst columns in the set A [row_start ... row_start + row_length-1]. + The columns under consideration are currently *not* in the degree lists, + and have already been placed in the hash buckets. + + The hash bucket for columns whose hash function is equal to h is stored + as follows: + + if head [h] is >= 0, then head [h] contains a degree list, so: + + head [h] is the first column in degree bucket h. + Col [head [h]].headhash gives the first column in hash bucket h. + + otherwise, the degree list is empty, and: + + -(head [h] + 2) is the first column in hash bucket h. + + For a column c in a hash bucket, Col [c].shared3.prev is NOT a "previous + column" pointer. Col [c].shared3.hash is used instead as the hash number + for that column. The value of Col [c].shared4.hash_next is the next column + in the same hash bucket. + + Assuming no, or "few" hash collisions, the time taken by this routine is + linear in the sum of the sizes (lengths) of each column whose score has + just been computed in the approximate degree computation. + Not user-callable. +*/ + +PRIVATE void detect_super_cols +( + /* === Parameters ======================================================= */ + +#ifndef NDEBUG + /* these two parameters are only needed when debugging is enabled: */ + Int n_col, /* number of columns of A */ + Colamd_Row Row [], /* of size n_row+1 */ +#endif /* NDEBUG */ + + Colamd_Col Col [], /* of size n_col+1 */ + Int A [], /* row indices of A */ + Int head [], /* head of degree lists and hash buckets */ + Int row_start, /* pointer to set of columns to check */ + Int row_length /* number of columns to check */ +) +{ + /* === Local variables ================================================== */ + + Int hash ; /* hash value for a column */ + Int *rp ; /* pointer to a row */ + Int c ; /* a column index */ + Int super_c ; /* column index of the column to absorb into */ + Int *cp1 ; /* column pointer for column super_c */ + Int *cp2 ; /* column pointer for column c */ + Int length ; /* length of column super_c */ + Int prev_c ; /* column preceding c in hash bucket */ + Int i ; /* loop counter */ + Int *rp_end ; /* pointer to the end of the row */ + Int col ; /* a column index in the row to check */ + Int head_column ; /* first column in hash bucket or degree list */ + Int first_col ; /* first column in hash bucket */ + + /* === Consider each column in the row ================================== */ + + rp = &A [row_start] ; + rp_end = rp + row_length ; + while (rp < rp_end) + { + col = *rp++ ; + if (COL_IS_DEAD (col)) + { + continue ; + } + + /* get hash number for this column */ + hash = Col [col].shared3.hash ; + ASSERT (hash <= n_col) ; + + /* === Get the first column in this hash bucket ===================== */ + + head_column = head [hash] ; + if (head_column > EMPTY) + { + first_col = Col [head_column].shared3.headhash ; + } + else + { + first_col = - (head_column + 2) ; + } + + /* === Consider each column in the hash bucket ====================== */ + + for (super_c = first_col ; super_c != EMPTY ; + super_c = Col [super_c].shared4.hash_next) + { + ASSERT (COL_IS_ALIVE (super_c)) ; + ASSERT (Col [super_c].shared3.hash == hash) ; + length = Col [super_c].length ; + + /* prev_c is the column preceding column c in the hash bucket */ + prev_c = super_c ; + + /* === Compare super_c with all columns after it ================ */ + + for (c = Col [super_c].shared4.hash_next ; + c != EMPTY ; c = Col [c].shared4.hash_next) + { + ASSERT (c != super_c) ; + ASSERT (COL_IS_ALIVE (c)) ; + ASSERT (Col [c].shared3.hash == hash) ; + + /* not identical if lengths or scores are different */ + if (Col [c].length != length || + Col [c].shared2.score != Col [super_c].shared2.score) + { + prev_c = c ; + continue ; + } + + /* compare the two columns */ + cp1 = &A [Col [super_c].start] ; + cp2 = &A [Col [c].start] ; + + for (i = 0 ; i < length ; i++) + { + /* the columns are "clean" (no dead rows) */ + ASSERT (ROW_IS_ALIVE (*cp1)) ; + ASSERT (ROW_IS_ALIVE (*cp2)) ; + /* row indices will same order for both supercols, */ + /* no gather scatter nessasary */ + if (*cp1++ != *cp2++) + { + break ; + } + } + + /* the two columns are different if the for-loop "broke" */ + if (i != length) + { + prev_c = c ; + continue ; + } + + /* === Got it! two columns are identical =================== */ + + ASSERT (Col [c].shared2.score == Col [super_c].shared2.score) ; + + Col [super_c].shared1.thickness += Col [c].shared1.thickness ; + Col [c].shared1.parent = super_c ; + KILL_NON_PRINCIPAL_COL (c) ; + /* order c later, in order_children() */ + Col [c].shared2.order = EMPTY ; + /* remove c from hash bucket */ + Col [prev_c].shared4.hash_next = Col [c].shared4.hash_next ; + } + } + + /* === Empty this hash bucket ======================================= */ + + if (head_column > EMPTY) + { + /* corresponding degree list "hash" is not empty */ + Col [head_column].shared3.headhash = EMPTY ; + } + else + { + /* corresponding degree list "hash" is empty */ + head [hash] = EMPTY ; + } + } +} + + +/* ========================================================================== */ +/* === garbage_collection =================================================== */ +/* ========================================================================== */ + +/* + Defragments and compacts columns and rows in the workspace A. Used when + all avaliable memory has been used while performing row merging. Returns + the index of the first free position in A, after garbage collection. The + time taken by this routine is linear is the size of the array A, which is + itself linear in the number of nonzeros in the input matrix. + Not user-callable. +*/ + +PRIVATE Int garbage_collection /* returns the new value of pfree */ +( + /* === Parameters ======================================================= */ + + Int n_row, /* number of rows */ + Int n_col, /* number of columns */ + Colamd_Row Row [], /* row info */ + Colamd_Col Col [], /* column info */ + Int A [], /* A [0 ... Alen-1] holds the matrix */ + Int *pfree /* &A [0] ... pfree is in use */ +) +{ + /* === Local variables ================================================== */ + + Int *psrc ; /* source pointer */ + Int *pdest ; /* destination pointer */ + Int j ; /* counter */ + Int r ; /* a row index */ + Int c ; /* a column index */ + Int length ; /* length of a row or column */ + +#ifndef NDEBUG + Int debug_rows ; + DEBUG2 (("Defrag..\n")) ; + for (psrc = &A[0] ; psrc < pfree ; psrc++) ASSERT (*psrc >= 0) ; + debug_rows = 0 ; +#endif /* NDEBUG */ + + /* === Defragment the columns =========================================== */ + + pdest = &A[0] ; + for (c = 0 ; c < n_col ; c++) + { + if (COL_IS_ALIVE (c)) + { + psrc = &A [Col [c].start] ; + + /* move and compact the column */ + ASSERT (pdest <= psrc) ; + Col [c].start = (Int) (pdest - &A [0]) ; + length = Col [c].length ; + for (j = 0 ; j < length ; j++) + { + r = *psrc++ ; + if (ROW_IS_ALIVE (r)) + { + *pdest++ = r ; + } + } + Col [c].length = (Int) (pdest - &A [Col [c].start]) ; + } + } + + /* === Prepare to defragment the rows =================================== */ + + for (r = 0 ; r < n_row ; r++) + { + if (ROW_IS_DEAD (r) || (Row [r].length == 0)) + { + /* This row is already dead, or is of zero length. Cannot compact + * a row of zero length, so kill it. NOTE: in the current version, + * there are no zero-length live rows. Kill the row (for the first + * time, or again) just to be safe. */ + KILL_ROW (r) ; + } + else + { + /* save first column index in Row [r].shared2.first_column */ + psrc = &A [Row [r].start] ; + Row [r].shared2.first_column = *psrc ; + ASSERT (ROW_IS_ALIVE (r)) ; + /* flag the start of the row with the one's complement of row */ + *psrc = ONES_COMPLEMENT (r) ; +#ifndef NDEBUG + debug_rows++ ; +#endif /* NDEBUG */ + } + } + + /* === Defragment the rows ============================================== */ + + psrc = pdest ; + while (psrc < pfree) + { + /* find a negative number ... the start of a row */ + if (*psrc++ < 0) + { + psrc-- ; + /* get the row index */ + r = ONES_COMPLEMENT (*psrc) ; + ASSERT (r >= 0 && r < n_row) ; + /* restore first column index */ + *psrc = Row [r].shared2.first_column ; + ASSERT (ROW_IS_ALIVE (r)) ; + ASSERT (Row [r].length > 0) ; + /* move and compact the row */ + ASSERT (pdest <= psrc) ; + Row [r].start = (Int) (pdest - &A [0]) ; + length = Row [r].length ; + for (j = 0 ; j < length ; j++) + { + c = *psrc++ ; + if (COL_IS_ALIVE (c)) + { + *pdest++ = c ; + } + } + Row [r].length = (Int) (pdest - &A [Row [r].start]) ; + ASSERT (Row [r].length > 0) ; +#ifndef NDEBUG + debug_rows-- ; +#endif /* NDEBUG */ + } + } + /* ensure we found all the rows */ + ASSERT (debug_rows == 0) ; + + /* === Return the new value of pfree ==================================== */ + + return ((Int) (pdest - &A [0])) ; +} + + +/* ========================================================================== */ +/* === clear_mark =========================================================== */ +/* ========================================================================== */ + +/* + Clears the Row [].shared2.mark array, and returns the new tag_mark. + Return value is the new tag_mark. Not user-callable. +*/ + +PRIVATE Int clear_mark /* return the new value for tag_mark */ +( + /* === Parameters ======================================================= */ + + Int tag_mark, /* new value of tag_mark */ + Int max_mark, /* max allowed value of tag_mark */ + + Int n_row, /* number of rows in A */ + Colamd_Row Row [] /* Row [0 ... n_row-1].shared2.mark is set to zero */ +) +{ + /* === Local variables ================================================== */ + + Int r ; + + if (tag_mark <= 0 || tag_mark >= max_mark) + { + for (r = 0 ; r < n_row ; r++) + { + if (ROW_IS_ALIVE (r)) + { + Row [r].shared2.mark = 0 ; + } + } + tag_mark = 1 ; + } + + return (tag_mark) ; +} + + +/* ========================================================================== */ +/* === print_report ========================================================= */ +/* ========================================================================== */ + +PRIVATE void print_report +( + char *method, + Int stats [COLAMD_STATS] +) +{ + + Int i1, i2, i3 ; + + PRINTF (("\n%s version %d.%d, %s: ", method, + COLAMD_MAIN_VERSION, COLAMD_SUB_VERSION, COLAMD_DATE)) ; + + if (!stats) + { + PRINTF (("No statistics available.\n")) ; + return ; + } + + i1 = stats [COLAMD_INFO1] ; + i2 = stats [COLAMD_INFO2] ; + i3 = stats [COLAMD_INFO3] ; + + if (stats [COLAMD_STATUS] >= 0) + { + PRINTF (("OK. ")) ; + } + else + { + PRINTF (("ERROR. ")) ; + } + + switch (stats [COLAMD_STATUS]) + { + + case COLAMD_OK_BUT_JUMBLED: + + PRINTF(("Matrix has unsorted or duplicate row indices.\n")) ; + + PRINTF(("%s: number of duplicate or out-of-order row indices: %d\n", + method, i3)) ; + + PRINTF(("%s: last seen duplicate or out-of-order row index: %d\n", + method, INDEX (i2))) ; + + PRINTF(("%s: last seen in column: %d", + method, INDEX (i1))) ; + + /* no break - fall through to next case instead */ + + case COLAMD_OK: + + PRINTF(("\n")) ; + + PRINTF(("%s: number of dense or empty rows ignored: %d\n", + method, stats [COLAMD_DENSE_ROW])) ; + + PRINTF(("%s: number of dense or empty columns ignored: %d\n", + method, stats [COLAMD_DENSE_COL])) ; + + PRINTF(("%s: number of garbage collections performed: %d\n", + method, stats [COLAMD_DEFRAG_COUNT])) ; + break ; + + case COLAMD_ERROR_A_not_present: + + PRINTF(("Array A (row indices of matrix) not present.\n")) ; + break ; + + case COLAMD_ERROR_p_not_present: + + PRINTF(("Array p (column pointers for matrix) not present.\n")) ; + break ; + + case COLAMD_ERROR_nrow_negative: + + PRINTF(("Invalid number of rows (%d).\n", i1)) ; + break ; + + case COLAMD_ERROR_ncol_negative: + + PRINTF(("Invalid number of columns (%d).\n", i1)) ; + break ; + + case COLAMD_ERROR_nnz_negative: + + PRINTF(("Invalid number of nonzero entries (%d).\n", i1)) ; + break ; + + case COLAMD_ERROR_p0_nonzero: + + PRINTF(("Invalid column pointer, p [0] = %d, must be zero.\n", i1)); + break ; + + case COLAMD_ERROR_A_too_small: + + PRINTF(("Array A too small.\n")) ; + PRINTF((" Need Alen >= %d, but given only Alen = %d.\n", + i1, i2)) ; + break ; + + case COLAMD_ERROR_col_length_negative: + + PRINTF + (("Column %d has a negative number of nonzero entries (%d).\n", + INDEX (i1), i2)) ; + break ; + + case COLAMD_ERROR_row_index_out_of_bounds: + + PRINTF + (("Row index (row %d) out of bounds (%d to %d) in column %d.\n", + INDEX (i2), INDEX (0), INDEX (i3-1), INDEX (i1))) ; + break ; + + case COLAMD_ERROR_out_of_memory: + + PRINTF(("Out of memory.\n")) ; + break ; + + /* v2.4: internal-error case deleted */ + } +} + + + + +/* ========================================================================== */ +/* === colamd debugging routines ============================================ */ +/* ========================================================================== */ + +/* When debugging is disabled, the remainder of this file is ignored. */ + +#ifndef NDEBUG + + +/* ========================================================================== */ +/* === debug_structures ===================================================== */ +/* ========================================================================== */ + +/* + At this point, all empty rows and columns are dead. All live columns + are "clean" (containing no dead rows) and simplicial (no supercolumns + yet). Rows may contain dead columns, but all live rows contain at + least one live column. +*/ + +PRIVATE void debug_structures +( + /* === Parameters ======================================================= */ + + Int n_row, + Int n_col, + Colamd_Row Row [], + Colamd_Col Col [], + Int A [], + Int n_col2 +) +{ + /* === Local variables ================================================== */ + + Int i ; + Int c ; + Int *cp ; + Int *cp_end ; + Int len ; + Int score ; + Int r ; + Int *rp ; + Int *rp_end ; + Int deg ; + + /* === Check A, Row, and Col ============================================ */ + + for (c = 0 ; c < n_col ; c++) + { + if (COL_IS_ALIVE (c)) + { + len = Col [c].length ; + score = Col [c].shared2.score ; + DEBUG4 (("initial live col %5d %5d %5d\n", c, len, score)) ; + ASSERT (len > 0) ; + ASSERT (score >= 0) ; + ASSERT (Col [c].shared1.thickness == 1) ; + cp = &A [Col [c].start] ; + cp_end = cp + len ; + while (cp < cp_end) + { + r = *cp++ ; + ASSERT (ROW_IS_ALIVE (r)) ; + } + } + else + { + i = Col [c].shared2.order ; + ASSERT (i >= n_col2 && i < n_col) ; + } + } + + for (r = 0 ; r < n_row ; r++) + { + if (ROW_IS_ALIVE (r)) + { + i = 0 ; + len = Row [r].length ; + deg = Row [r].shared1.degree ; + ASSERT (len > 0) ; + ASSERT (deg > 0) ; + rp = &A [Row [r].start] ; + rp_end = rp + len ; + while (rp < rp_end) + { + c = *rp++ ; + if (COL_IS_ALIVE (c)) + { + i++ ; + } + } + ASSERT (i > 0) ; + } + } +} + + +/* ========================================================================== */ +/* === debug_deg_lists ====================================================== */ +/* ========================================================================== */ + +/* + Prints the contents of the degree lists. Counts the number of columns + in the degree list and compares it to the total it should have. Also + checks the row degrees. +*/ + +PRIVATE void debug_deg_lists +( + /* === Parameters ======================================================= */ + + Int n_row, + Int n_col, + Colamd_Row Row [], + Colamd_Col Col [], + Int head [], + Int min_score, + Int should, + Int max_deg +) +{ + /* === Local variables ================================================== */ + + Int deg ; + Int col ; + Int have ; + Int row ; + + /* === Check the degree lists =========================================== */ + + if (n_col > 10000 && colamd_debug <= 0) + { + return ; + } + have = 0 ; + DEBUG4 (("Degree lists: %d\n", min_score)) ; + for (deg = 0 ; deg <= n_col ; deg++) + { + col = head [deg] ; + if (col == EMPTY) + { + continue ; + } + DEBUG4 (("%d:", deg)) ; + while (col != EMPTY) + { + DEBUG4 ((" %d", col)) ; + have += Col [col].shared1.thickness ; + ASSERT (COL_IS_ALIVE (col)) ; + col = Col [col].shared4.degree_next ; + } + DEBUG4 (("\n")) ; + } + DEBUG4 (("should %d have %d\n", should, have)) ; + ASSERT (should == have) ; + + /* === Check the row degrees ============================================ */ + + if (n_row > 10000 && colamd_debug <= 0) + { + return ; + } + for (row = 0 ; row < n_row ; row++) + { + if (ROW_IS_ALIVE (row)) + { + ASSERT (Row [row].shared1.degree <= max_deg) ; + } + } +} + + +/* ========================================================================== */ +/* === debug_mark =========================================================== */ +/* ========================================================================== */ + +/* + Ensures that the tag_mark is less that the maximum and also ensures that + each entry in the mark array is less than the tag mark. +*/ + +PRIVATE void debug_mark +( + /* === Parameters ======================================================= */ + + Int n_row, + Colamd_Row Row [], + Int tag_mark, + Int max_mark +) +{ + /* === Local variables ================================================== */ + + Int r ; + + /* === Check the Row marks ============================================== */ + + ASSERT (tag_mark > 0 && tag_mark <= max_mark) ; + if (n_row > 10000 && colamd_debug <= 0) + { + return ; + } + for (r = 0 ; r < n_row ; r++) + { + ASSERT (Row [r].shared2.mark < tag_mark) ; + } +} + + +/* ========================================================================== */ +/* === debug_matrix ========================================================= */ +/* ========================================================================== */ + +/* + Prints out the contents of the columns and the rows. +*/ + +PRIVATE void debug_matrix +( + /* === Parameters ======================================================= */ + + Int n_row, + Int n_col, + Colamd_Row Row [], + Colamd_Col Col [], + Int A [] +) +{ + /* === Local variables ================================================== */ + + Int r ; + Int c ; + Int *rp ; + Int *rp_end ; + Int *cp ; + Int *cp_end ; + + /* === Dump the rows and columns of the matrix ========================== */ + + if (colamd_debug < 3) + { + return ; + } + DEBUG3 (("DUMP MATRIX:\n")) ; + for (r = 0 ; r < n_row ; r++) + { + DEBUG3 (("Row %d alive? %d\n", r, ROW_IS_ALIVE (r))) ; + if (ROW_IS_DEAD (r)) + { + continue ; + } + DEBUG3 (("start %d length %d degree %d\n", + Row [r].start, Row [r].length, Row [r].shared1.degree)) ; + rp = &A [Row [r].start] ; + rp_end = rp + Row [r].length ; + while (rp < rp_end) + { + c = *rp++ ; + DEBUG4 ((" %d col %d\n", COL_IS_ALIVE (c), c)) ; + } + } + + for (c = 0 ; c < n_col ; c++) + { + DEBUG3 (("Col %d alive? %d\n", c, COL_IS_ALIVE (c))) ; + if (COL_IS_DEAD (c)) + { + continue ; + } + DEBUG3 (("start %d length %d shared1 %d shared2 %d\n", + Col [c].start, Col [c].length, + Col [c].shared1.thickness, Col [c].shared2.score)) ; + cp = &A [Col [c].start] ; + cp_end = cp + Col [c].length ; + while (cp < cp_end) + { + r = *cp++ ; + DEBUG4 ((" %d row %d\n", ROW_IS_ALIVE (r), r)) ; + } + } +} + +PRIVATE void colamd_get_debug +( + char *method +) +{ + FILE *f ; + colamd_debug = 0 ; /* no debug printing */ + f = fopen ("debug", "r") ; + if (f == (FILE *) NULL) + { + colamd_debug = 0 ; + } + else + { + fscanf (f, "%d", &colamd_debug) ; + fclose (f) ; + } + DEBUG0 (("%s: debug version, D = %d (THIS WILL BE SLOW!)\n", + method, colamd_debug)) ; +} + +#endif /* NDEBUG */