alpar@1: /* glpspm.c */
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  This code is part of GLPK (GNU Linear Programming Kit).
alpar@1: *
alpar@1: *  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
alpar@1: *  2009, 2010 Andrew Makhorin, Department for Applied Informatics,
alpar@1: *  Moscow Aviation Institute, Moscow, Russia. All rights reserved.
alpar@1: *  E-mail: <mao@gnu.org>.
alpar@1: *
alpar@1: *  GLPK is free software: you can redistribute it and/or modify it
alpar@1: *  under the terms of the GNU General Public License as published by
alpar@1: *  the Free Software Foundation, either version 3 of the License, or
alpar@1: *  (at your option) any later version.
alpar@1: *
alpar@1: *  GLPK is distributed in the hope that it will be useful, but WITHOUT
alpar@1: *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
alpar@1: *  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
alpar@1: *  License for more details.
alpar@1: *
alpar@1: *  You should have received a copy of the GNU General Public License
alpar@1: *  along with GLPK. If not, see <http://www.gnu.org/licenses/>.
alpar@1: ***********************************************************************/
alpar@1: 
alpar@1: #include "glphbm.h"
alpar@1: #include "glprgr.h"
alpar@1: #include "glpspm.h"
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_create_mat - create general sparse matrix
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  SPM *spm_create_mat(int m, int n);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine spm_create_mat creates a general sparse matrix having
alpar@1: *  m rows and n columns. Being created the matrix is zero (empty), i.e.
alpar@1: *  has no elements.
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  The routine returns a pointer to the matrix created. */
alpar@1: 
alpar@1: SPM *spm_create_mat(int m, int n)
alpar@1: {     SPM *A;
alpar@1:       xassert(0 <= m && m < INT_MAX);
alpar@1:       xassert(0 <= n && n < INT_MAX);
alpar@1:       A = xmalloc(sizeof(SPM));
alpar@1:       A->m = m;
alpar@1:       A->n = n;
alpar@1:       if (m == 0 || n == 0)
alpar@1:       {  A->pool = NULL;
alpar@1:          A->row = NULL;
alpar@1:          A->col = NULL;
alpar@1:       }
alpar@1:       else
alpar@1:       {  int i, j;
alpar@1:          A->pool = dmp_create_pool();
alpar@1:          A->row = xcalloc(1+m, sizeof(SPME *));
alpar@1:          for (i = 1; i <= m; i++) A->row[i] = NULL;
alpar@1:          A->col = xcalloc(1+n, sizeof(SPME *));
alpar@1:          for (j = 1; j <= n; j++) A->col[j] = NULL;
alpar@1:       }
alpar@1:       return A;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_new_elem - add new element to sparse matrix
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  SPME *spm_new_elem(SPM *A, int i, int j, double val);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine spm_new_elem adds a new element to the specified sparse
alpar@1: *  matrix. Parameters i, j, and val specify the row number, the column
alpar@1: *  number, and a numerical value of the element, respectively.
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  The routine returns a pointer to the new element added. */
alpar@1: 
alpar@1: SPME *spm_new_elem(SPM *A, int i, int j, double val)
alpar@1: {     SPME *e;
alpar@1:       xassert(1 <= i && i <= A->m);
alpar@1:       xassert(1 <= j && j <= A->n);
alpar@1:       e = dmp_get_atom(A->pool, sizeof(SPME));
alpar@1:       e->i = i;
alpar@1:       e->j = j;
alpar@1:       e->val = val;
alpar@1:       e->r_prev = NULL;
alpar@1:       e->r_next = A->row[i];
alpar@1:       if (e->r_next != NULL) e->r_next->r_prev = e;
alpar@1:       e->c_prev = NULL;
alpar@1:       e->c_next = A->col[j];
alpar@1:       if (e->c_next != NULL) e->c_next->c_prev = e;
alpar@1:       A->row[i] = A->col[j] = e;
alpar@1:       return e;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_delete_mat - delete general sparse matrix
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  void spm_delete_mat(SPM *A);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine deletes the specified general sparse matrix freeing all
alpar@1: *  the memory allocated to this object. */
alpar@1: 
alpar@1: void spm_delete_mat(SPM *A)
alpar@1: {     /* delete sparse matrix */
alpar@1:       if (A->pool != NULL) dmp_delete_pool(A->pool);
alpar@1:       if (A->row != NULL) xfree(A->row);
alpar@1:       if (A->col != NULL) xfree(A->col);
alpar@1:       xfree(A);
alpar@1:       return;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_test_mat_e - create test sparse matrix of E(n,c) class
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  SPM *spm_test_mat_e(int n, int c);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine spm_test_mat_e creates a test sparse matrix of E(n,c)
alpar@1: *  class as described in the book: Ole 0sterby, Zahari Zlatev. Direct
alpar@1: *  Methods for Sparse Matrices. Springer-Verlag, 1983.
alpar@1: *
alpar@1: *  Matrix of E(n,c) class is a symmetric positive definite matrix of
alpar@1: *  the order n. It has the number 4 on its main diagonal and the number
alpar@1: *  -1 on its four co-diagonals, two of which are neighbour to the main
alpar@1: *  diagonal and two others are shifted from the main diagonal on the
alpar@1: *  distance c.
alpar@1: *
alpar@1: *  It is necessary that n >= 3 and 2 <= c <= n-1.
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  The routine returns a pointer to the matrix created. */
alpar@1: 
alpar@1: SPM *spm_test_mat_e(int n, int c)
alpar@1: {     SPM *A;
alpar@1:       int i;
alpar@1:       xassert(n >= 3 && 2 <= c && c <= n-1);
alpar@1:       A = spm_create_mat(n, n);
alpar@1:       for (i = 1; i <= n; i++)
alpar@1:          spm_new_elem(A, i, i, 4.0);
alpar@1:       for (i = 1; i <= n-1; i++)
alpar@1:       {  spm_new_elem(A, i, i+1, -1.0);
alpar@1:          spm_new_elem(A, i+1, i, -1.0);
alpar@1:       }
alpar@1:       for (i = 1; i <= n-c; i++)
alpar@1:       {  spm_new_elem(A, i, i+c, -1.0);
alpar@1:          spm_new_elem(A, i+c, i, -1.0);
alpar@1:       }
alpar@1:       return A;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_test_mat_d - create test sparse matrix of D(n,c) class
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  SPM *spm_test_mat_d(int n, int c);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine spm_test_mat_d creates a test sparse matrix of D(n,c)
alpar@1: *  class as described in the book: Ole 0sterby, Zahari Zlatev. Direct
alpar@1: *  Methods for Sparse Matrices. Springer-Verlag, 1983.
alpar@1: *
alpar@1: *  Matrix of D(n,c) class is a non-singular matrix of the order n. It
alpar@1: *  has unity main diagonal, three co-diagonals above the main diagonal
alpar@1: *  on the distance c, which are cyclically continued below the main
alpar@1: *  diagonal, and a triangle block of the size 10x10 in the upper right
alpar@1: *  corner.
alpar@1: *
alpar@1: *  It is necessary that n >= 14 and 1 <= c <= n-13.
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  The routine returns a pointer to the matrix created. */
alpar@1: 
alpar@1: SPM *spm_test_mat_d(int n, int c)
alpar@1: {     SPM *A;
alpar@1:       int i, j;
alpar@1:       xassert(n >= 14 && 1 <= c && c <= n-13);
alpar@1:       A = spm_create_mat(n, n);
alpar@1:       for (i = 1; i <= n; i++)
alpar@1:          spm_new_elem(A, i, i, 1.0);
alpar@1:       for (i = 1; i <= n-c; i++)
alpar@1:          spm_new_elem(A, i, i+c, (double)(i+1));
alpar@1:       for (i = n-c+1; i <= n; i++)
alpar@1:          spm_new_elem(A, i, i-n+c, (double)(i+1));
alpar@1:       for (i = 1; i <= n-c-1; i++)
alpar@1:          spm_new_elem(A, i, i+c+1, (double)(-i));
alpar@1:       for (i = n-c; i <= n; i++)
alpar@1:          spm_new_elem(A, i, i-n+c+1, (double)(-i));
alpar@1:       for (i = 1; i <= n-c-2; i++)
alpar@1:          spm_new_elem(A, i, i+c+2, 16.0);
alpar@1:       for (i = n-c-1; i <= n; i++)
alpar@1:          spm_new_elem(A, i, i-n+c+2, 16.0);
alpar@1:       for (j = 1; j <= 10; j++)
alpar@1:          for (i = 1; i <= 11-j; i++)
alpar@1:             spm_new_elem(A, i, n-11+i+j, 100.0 * (double)j);
alpar@1:       return A;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_show_mat - write sparse matrix pattern in BMP file format
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  int spm_show_mat(const SPM *A, const char *fname);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine spm_show_mat writes pattern of the specified sparse
alpar@1: *  matrix in uncompressed BMP file format (Windows bitmap) to a binary
alpar@1: *  file whose name is specified by the character string fname.
alpar@1: *
alpar@1: *  Each pixel corresponds to one matrix element. The pixel colors have
alpar@1: *  the following meaning:
alpar@1: *
alpar@1: *  Black    structurally zero element
alpar@1: *  White    positive element
alpar@1: *  Cyan     negative element
alpar@1: *  Green    zero element
alpar@1: *  Red      duplicate element
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  If no error occured, the routine returns zero. Otherwise, it prints
alpar@1: *  an appropriate error message and returns non-zero. */
alpar@1: 
alpar@1: int spm_show_mat(const SPM *A, const char *fname)
alpar@1: {     int m = A->m;
alpar@1:       int n = A->n;
alpar@1:       int i, j, k, ret;
alpar@1:       char *map;
alpar@1:       xprintf("spm_show_mat: writing matrix pattern to `%s'...\n",
alpar@1:          fname);
alpar@1:       xassert(1 <= m && m <= 32767);
alpar@1:       xassert(1 <= n && n <= 32767);
alpar@1:       map = xmalloc(m * n);
alpar@1:       memset(map, 0x08, m * n);
alpar@1:       for (i = 1; i <= m; i++)
alpar@1:       {  SPME *e;
alpar@1:          for (e = A->row[i]; e != NULL; e = e->r_next)
alpar@1:          {  j = e->j;
alpar@1:             xassert(1 <= j && j <= n);
alpar@1:             k = n * (i - 1) + (j - 1);
alpar@1:             if (map[k] != 0x08)
alpar@1:                map[k] = 0x0C;
alpar@1:             else if (e->val > 0.0)
alpar@1:                map[k] = 0x0F;
alpar@1:             else if (e->val < 0.0)
alpar@1:                map[k] = 0x0B;
alpar@1:             else
alpar@1:                map[k] = 0x0A;
alpar@1:          }
alpar@1:       }
alpar@1:       ret = rgr_write_bmp16(fname, m, n, map);
alpar@1:       xfree(map);
alpar@1:       return ret;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_read_hbm - read sparse matrix in Harwell-Boeing format
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  SPM *spm_read_hbm(const char *fname);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine spm_read_hbm reads a sparse matrix in the Harwell-Boeing
alpar@1: *  format from a text file whose name is the character string fname.
alpar@1: *
alpar@1: *  Detailed description of the Harwell-Boeing format recognised by this
alpar@1: *  routine can be found in the following report:
alpar@1: *
alpar@1: *  I.S.Duff, R.G.Grimes, J.G.Lewis. User's Guide for the Harwell-Boeing
alpar@1: *  Sparse Matrix Collection (Release I), TR/PA/92/86, October 1992.
alpar@1: *
alpar@1: *  NOTE
alpar@1: *
alpar@1: *  The routine spm_read_hbm reads the matrix "as is", due to which zero
alpar@1: *  and/or duplicate elements can appear in the matrix.
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  If no error occured, the routine returns a pointer to the matrix
alpar@1: *  created. Otherwise, the routine prints an appropriate error message
alpar@1: *  and returns NULL. */
alpar@1: 
alpar@1: SPM *spm_read_hbm(const char *fname)
alpar@1: {     SPM *A = NULL;
alpar@1:       HBM *hbm;
alpar@1:       int nrow, ncol, nnzero, i, j, beg, end, ptr, *colptr, *rowind;
alpar@1:       double val, *values;
alpar@1:       char *mxtype;
alpar@1:       hbm = hbm_read_mat(fname);
alpar@1:       if (hbm == NULL)
alpar@1:       {  xprintf("spm_read_hbm: unable to read matrix\n");
alpar@1:          goto fini;
alpar@1:       }
alpar@1:       mxtype = hbm->mxtype;
alpar@1:       nrow = hbm->nrow;
alpar@1:       ncol = hbm->ncol;
alpar@1:       nnzero = hbm->nnzero;
alpar@1:       colptr = hbm->colptr;
alpar@1:       rowind = hbm->rowind;
alpar@1:       values = hbm->values;
alpar@1:       if (!(strcmp(mxtype, "RSA") == 0 || strcmp(mxtype, "PSA") == 0 ||
alpar@1:             strcmp(mxtype, "RUA") == 0 || strcmp(mxtype, "PUA") == 0 ||
alpar@1:             strcmp(mxtype, "RRA") == 0 || strcmp(mxtype, "PRA") == 0))
alpar@1:       {  xprintf("spm_read_hbm: matrix type `%s' not supported\n",
alpar@1:             mxtype);
alpar@1:          goto fini;
alpar@1:       }
alpar@1:       A = spm_create_mat(nrow, ncol);
alpar@1:       if (mxtype[1] == 'S' || mxtype[1] == 'U')
alpar@1:          xassert(nrow == ncol);
alpar@1:       for (j = 1; j <= ncol; j++)
alpar@1:       {  beg = colptr[j];
alpar@1:          end = colptr[j+1];
alpar@1:          xassert(1 <= beg && beg <= end && end <= nnzero + 1);
alpar@1:          for (ptr = beg; ptr < end; ptr++)
alpar@1:          {  i = rowind[ptr];
alpar@1:             xassert(1 <= i && i <= nrow);
alpar@1:             if (mxtype[0] == 'R')
alpar@1:                val = values[ptr];
alpar@1:             else
alpar@1:                val = 1.0;
alpar@1:             spm_new_elem(A, i, j, val);
alpar@1:             if (mxtype[1] == 'S' && i != j)
alpar@1:                spm_new_elem(A, j, i, val);
alpar@1:          }
alpar@1:       }
alpar@1: fini: if (hbm != NULL) hbm_free_mat(hbm);
alpar@1:       return A;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_count_nnz - determine number of non-zeros in sparse matrix
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  int spm_count_nnz(const SPM *A);
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  The routine spm_count_nnz returns the number of structural non-zero
alpar@1: *  elements in the specified sparse matrix. */
alpar@1: 
alpar@1: int spm_count_nnz(const SPM *A)
alpar@1: {     SPME *e;
alpar@1:       int i, nnz = 0;
alpar@1:       for (i = 1; i <= A->m; i++)
alpar@1:          for (e = A->row[i]; e != NULL; e = e->r_next) nnz++;
alpar@1:       return nnz;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_drop_zeros - remove zero elements from sparse matrix
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  int spm_drop_zeros(SPM *A, double eps);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine spm_drop_zeros removes all elements from the specified
alpar@1: *  sparse matrix, whose absolute value is less than eps.
alpar@1: *
alpar@1: *  If the parameter eps is 0, only zero elements are removed from the
alpar@1: *  matrix.
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  The routine returns the number of elements removed. */
alpar@1: 
alpar@1: int spm_drop_zeros(SPM *A, double eps)
alpar@1: {     SPME *e, *next;
alpar@1:       int i, count = 0;
alpar@1:       for (i = 1; i <= A->m; i++)
alpar@1:       {  for (e = A->row[i]; e != NULL; e = next)
alpar@1:          {  next = e->r_next;
alpar@1:             if (e->val == 0.0 || fabs(e->val) < eps)
alpar@1:             {  /* remove element from the row list */
alpar@1:                if (e->r_prev == NULL)
alpar@1:                   A->row[e->i] = e->r_next;
alpar@1:                else
alpar@1:                   e->r_prev->r_next = e->r_next;
alpar@1:                if (e->r_next == NULL)
alpar@1:                   ;
alpar@1:                else
alpar@1:                   e->r_next->r_prev = e->r_prev;
alpar@1:                /* remove element from the column list */
alpar@1:                if (e->c_prev == NULL)
alpar@1:                   A->col[e->j] = e->c_next;
alpar@1:                else
alpar@1:                   e->c_prev->c_next = e->c_next;
alpar@1:                if (e->c_next == NULL)
alpar@1:                   ;
alpar@1:                else
alpar@1:                   e->c_next->c_prev = e->c_prev;
alpar@1:                /* return element to the memory pool */
alpar@1:                dmp_free_atom(A->pool, e, sizeof(SPME));
alpar@1:                count++;
alpar@1:             }
alpar@1:          }
alpar@1:       }
alpar@1:       return count;
alpar@1: }
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_read_mat - read sparse matrix from text file
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  SPM *spm_read_mat(const char *fname);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine reads a sparse matrix from a text file whose name is
alpar@1: *  specified by the parameter fname.
alpar@1: *
alpar@1: *  For the file format see description of the routine spm_write_mat.
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  On success the routine returns a pointer to the matrix created,
alpar@1: *  otherwise NULL. */
alpar@1: 
alpar@1: #if 1
alpar@1: SPM *spm_read_mat(const char *fname)
alpar@1: {     xassert(fname != fname);
alpar@1:       return NULL;
alpar@1: }
alpar@1: #else
alpar@1: SPM *spm_read_mat(const char *fname)
alpar@1: {     SPM *A = NULL;
alpar@1:       PDS *pds;
alpar@1:       jmp_buf jump;
alpar@1:       int i, j, k, m, n, nnz, fail = 0;
alpar@1:       double val;
alpar@1:       xprintf("spm_read_mat: reading matrix from `%s'...\n", fname);
alpar@1:       pds = pds_open_file(fname);
alpar@1:       if (pds == NULL)
alpar@1:       {  xprintf("spm_read_mat: unable to open `%s' - %s\n", fname,
alpar@1:             strerror(errno));
alpar@1:          fail = 1;
alpar@1:          goto done;
alpar@1:       }
alpar@1:       if (setjmp(jump))
alpar@1:       {  fail = 1;
alpar@1:          goto done;
alpar@1:       }
alpar@1:       pds_set_jump(pds, jump);
alpar@1:       /* number of rows, number of columns, number of non-zeros */
alpar@1:       m = pds_scan_int(pds);
alpar@1:       if (m < 0)
alpar@1:          pds_error(pds, "invalid number of rows\n");
alpar@1:       n = pds_scan_int(pds);
alpar@1:       if (n < 0)
alpar@1:          pds_error(pds, "invalid number of columns\n");
alpar@1:       nnz = pds_scan_int(pds);
alpar@1:       if (nnz < 0)
alpar@1:          pds_error(pds, "invalid number of non-zeros\n");
alpar@1:       /* create matrix */
alpar@1:       xprintf("spm_read_mat: %d rows, %d columns, %d non-zeros\n",
alpar@1:          m, n, nnz);
alpar@1:       A = spm_create_mat(m, n);
alpar@1:       /* read matrix elements */
alpar@1:       for (k = 1; k <= nnz; k++)
alpar@1:       {  /* row index, column index, element value */
alpar@1:          i = pds_scan_int(pds);
alpar@1:          if (!(1 <= i && i <= m))
alpar@1:             pds_error(pds, "row index out of range\n");
alpar@1:          j = pds_scan_int(pds);
alpar@1:          if (!(1 <= j && j <= n))
alpar@1:             pds_error(pds, "column index out of range\n");
alpar@1:          val = pds_scan_num(pds);
alpar@1:          /* add new element to the matrix */
alpar@1:          spm_new_elem(A, i, j, val);
alpar@1:       }
alpar@1:       xprintf("spm_read_mat: %d lines were read\n", pds->count);
alpar@1: done: if (pds != NULL) pds_close_file(pds);
alpar@1:       if (fail && A != NULL) spm_delete_mat(A), A = NULL;
alpar@1:       return A;
alpar@1: }
alpar@1: #endif
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_write_mat - write sparse matrix to text file
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  int spm_write_mat(const SPM *A, const char *fname);
alpar@1: *
alpar@1: *  DESCRIPTION
alpar@1: *
alpar@1: *  The routine spm_write_mat writes the specified sparse matrix to a
alpar@1: *  text file whose name is specified by the parameter fname. This file
alpar@1: *  can be read back with the routine spm_read_mat.
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  On success the routine returns zero, otherwise non-zero.
alpar@1: *
alpar@1: *  FILE FORMAT
alpar@1: *
alpar@1: *  The file created by the routine spm_write_mat is a plain text file,
alpar@1: *  which contains the following information:
alpar@1: *
alpar@1: *     m n nnz
alpar@1: *     row[1] col[1] val[1]
alpar@1: *     row[2] col[2] val[2]
alpar@1: *     . . .
alpar@1: *     row[nnz] col[nnz] val[nnz]
alpar@1: *
alpar@1: *  where:
alpar@1: *  m is the number of rows;
alpar@1: *  n is the number of columns;
alpar@1: *  nnz is the number of non-zeros;
alpar@1: *  row[k], k = 1,...,nnz, are row indices;
alpar@1: *  col[k], k = 1,...,nnz, are column indices;
alpar@1: *  val[k], k = 1,...,nnz, are element values. */
alpar@1: 
alpar@1: #if 1
alpar@1: int spm_write_mat(const SPM *A, const char *fname)
alpar@1: {     xassert(A != A);
alpar@1:       xassert(fname != fname);
alpar@1:       return 0;
alpar@1: }
alpar@1: #else
alpar@1: int spm_write_mat(const SPM *A, const char *fname)
alpar@1: {     FILE *fp;
alpar@1:       int i, nnz, ret = 0;
alpar@1:       xprintf("spm_write_mat: writing matrix to `%s'...\n", fname);
alpar@1:       fp = fopen(fname, "w");
alpar@1:       if (fp == NULL)
alpar@1:       {  xprintf("spm_write_mat: unable to create `%s' - %s\n", fname,
alpar@1:             strerror(errno));
alpar@1:          ret = 1;
alpar@1:          goto done;
alpar@1:       }
alpar@1:       /* number of rows, number of columns, number of non-zeros */
alpar@1:       nnz = spm_count_nnz(A);
alpar@1:       fprintf(fp, "%d %d %d\n", A->m, A->n, nnz);
alpar@1:       /* walk through rows of the matrix */
alpar@1:       for (i = 1; i <= A->m; i++)
alpar@1:       {  SPME *e;
alpar@1:          /* walk through elements of i-th row */
alpar@1:          for (e = A->row[i]; e != NULL; e = e->r_next)
alpar@1:          {  /* row index, column index, element value */
alpar@1:             fprintf(fp, "%d %d %.*g\n", e->i, e->j, DBL_DIG, e->val);
alpar@1:          }
alpar@1:       }
alpar@1:       fflush(fp);
alpar@1:       if (ferror(fp))
alpar@1:       {  xprintf("spm_write_mat: writing error on `%s' - %s\n", fname,
alpar@1:             strerror(errno));
alpar@1:          ret = 1;
alpar@1:          goto done;
alpar@1:       }
alpar@1:       xprintf("spm_write_mat: %d lines were written\n", 1 + nnz);
alpar@1: done: if (fp != NULL) fclose(fp);
alpar@1:       return ret;
alpar@1: }
alpar@1: #endif
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  NAME
alpar@1: *
alpar@1: *  spm_transpose - transpose sparse matrix
alpar@1: *
alpar@1: *  SYNOPSIS
alpar@1: *
alpar@1: *  #include "glpspm.h"
alpar@1: *  SPM *spm_transpose(const SPM *A);
alpar@1: *
alpar@1: *  RETURNS
alpar@1: *
alpar@1: *  The routine computes and returns sparse matrix B, which is a matrix
alpar@1: *  transposed to sparse matrix A. */
alpar@1: 
alpar@1: SPM *spm_transpose(const SPM *A)
alpar@1: {     SPM *B;
alpar@1:       int i;
alpar@1:       B = spm_create_mat(A->n, A->m);
alpar@1:       for (i = 1; i <= A->m; i++)
alpar@1:       {  SPME *e;
alpar@1:          for (e = A->row[i]; e != NULL; e = e->r_next)
alpar@1:             spm_new_elem(B, e->j, i, e->val);
alpar@1:       }
alpar@1:       return B;
alpar@1: }
alpar@1: 
alpar@1: SPM *spm_add_sym(const SPM *A, const SPM *B)
alpar@1: {     /* add two sparse matrices (symbolic phase) */
alpar@1:       SPM *C;
alpar@1:       int i, j, *flag;
alpar@1:       xassert(A->m == B->m);
alpar@1:       xassert(A->n == B->n);
alpar@1:       /* create resultant matrix */
alpar@1:       C = spm_create_mat(A->m, A->n);
alpar@1:       /* allocate and clear the flag array */
alpar@1:       flag = xcalloc(1+C->n, sizeof(int));
alpar@1:       for (j = 1; j <= C->n; j++)
alpar@1:          flag[j] = 0;
alpar@1:       /* compute pattern of C = A + B */
alpar@1:       for (i = 1; i <= C->m; i++)
alpar@1:       {  SPME *e;
alpar@1:          /* at the beginning i-th row of C is empty */
alpar@1:          /* (i-th row of C) := (i-th row of C) union (i-th row of A) */
alpar@1:          for (e = A->row[i]; e != NULL; e = e->r_next)
alpar@1:          {  /* (note that i-th row of A may have duplicate elements) */
alpar@1:             j = e->j;
alpar@1:             if (!flag[j])
alpar@1:             {  spm_new_elem(C, i, j, 0.0);
alpar@1:                flag[j] = 1;
alpar@1:             }
alpar@1:          }
alpar@1:          /* (i-th row of C) := (i-th row of C) union (i-th row of B) */
alpar@1:          for (e = B->row[i]; e != NULL; e = e->r_next)
alpar@1:          {  /* (note that i-th row of B may have duplicate elements) */
alpar@1:             j = e->j;
alpar@1:             if (!flag[j])
alpar@1:             {  spm_new_elem(C, i, j, 0.0);
alpar@1:                flag[j] = 1;
alpar@1:             }
alpar@1:          }
alpar@1:          /* reset the flag array */
alpar@1:          for (e = C->row[i]; e != NULL; e = e->r_next)
alpar@1:             flag[e->j] = 0;
alpar@1:       }
alpar@1:       /* check and deallocate the flag array */
alpar@1:       for (j = 1; j <= C->n; j++)
alpar@1:          xassert(!flag[j]);
alpar@1:       xfree(flag);
alpar@1:       return C;
alpar@1: }
alpar@1: 
alpar@1: void spm_add_num(SPM *C, double alfa, const SPM *A, double beta,
alpar@1:       const SPM *B)
alpar@1: {     /* add two sparse matrices (numeric phase) */
alpar@1:       int i, j;
alpar@1:       double *work;
alpar@1:       /* allocate and clear the working array */
alpar@1:       work = xcalloc(1+C->n, sizeof(double));
alpar@1:       for (j = 1; j <= C->n; j++)
alpar@1:          work[j] = 0.0;
alpar@1:       /* compute matrix C = alfa * A + beta * B */
alpar@1:       for (i = 1; i <= C->n; i++)
alpar@1:       {  SPME *e;
alpar@1:          /* work := alfa * (i-th row of A) + beta * (i-th row of B) */
alpar@1:          /* (note that A and/or B may have duplicate elements) */
alpar@1:          for (e = A->row[i]; e != NULL; e = e->r_next)
alpar@1:             work[e->j] += alfa * e->val;
alpar@1:          for (e = B->row[i]; e != NULL; e = e->r_next)
alpar@1:             work[e->j] += beta * e->val;
alpar@1:          /* (i-th row of C) := work, work := 0 */
alpar@1:          for (e = C->row[i]; e != NULL; e = e->r_next)
alpar@1:          {  j = e->j;
alpar@1:             e->val = work[j];
alpar@1:             work[j] = 0.0;
alpar@1:          }
alpar@1:       }
alpar@1:       /* check and deallocate the working array */
alpar@1:       for (j = 1; j <= C->n; j++)
alpar@1:          xassert(work[j] == 0.0);
alpar@1:       xfree(work);
alpar@1:       return;
alpar@1: }
alpar@1: 
alpar@1: SPM *spm_add_mat(double alfa, const SPM *A, double beta, const SPM *B)
alpar@1: {     /* add two sparse matrices (driver routine) */
alpar@1:       SPM *C;
alpar@1:       C = spm_add_sym(A, B);
alpar@1:       spm_add_num(C, alfa, A, beta, B);
alpar@1:       return C;
alpar@1: }
alpar@1: 
alpar@1: SPM *spm_mul_sym(const SPM *A, const SPM *B)
alpar@1: {     /* multiply two sparse matrices (symbolic phase) */
alpar@1:       int i, j, k, *flag;
alpar@1:       SPM *C;
alpar@1:       xassert(A->n == B->m);
alpar@1:       /* create resultant matrix */
alpar@1:       C = spm_create_mat(A->m, B->n);
alpar@1:       /* allocate and clear the flag array */
alpar@1:       flag = xcalloc(1+C->n, sizeof(int));
alpar@1:       for (j = 1; j <= C->n; j++)
alpar@1:          flag[j] = 0;
alpar@1:       /* compute pattern of C = A * B */
alpar@1:       for (i = 1; i <= C->m; i++)
alpar@1:       {  SPME *e, *ee;
alpar@1:          /* compute pattern of i-th row of C */
alpar@1:          for (e = A->row[i]; e != NULL; e = e->r_next)
alpar@1:          {  k = e->j;
alpar@1:             for (ee = B->row[k]; ee != NULL; ee = ee->r_next)
alpar@1:             {  j = ee->j;
alpar@1:                /* if a[i,k] != 0 and b[k,j] != 0 then c[i,j] != 0 */
alpar@1:                if (!flag[j])
alpar@1:                {  /* c[i,j] does not exist, so create it */
alpar@1:                   spm_new_elem(C, i, j, 0.0);
alpar@1:                   flag[j] = 1;
alpar@1:                }
alpar@1:             }
alpar@1:          }
alpar@1:          /* reset the flag array */
alpar@1:          for (e = C->row[i]; e != NULL; e = e->r_next)
alpar@1:             flag[e->j] = 0;
alpar@1:       }
alpar@1:       /* check and deallocate the flag array */
alpar@1:       for (j = 1; j <= C->n; j++)
alpar@1:          xassert(!flag[j]);
alpar@1:       xfree(flag);
alpar@1:       return C;
alpar@1: }
alpar@1: 
alpar@1: void spm_mul_num(SPM *C, const SPM *A, const SPM *B)
alpar@1: {     /* multiply two sparse matrices (numeric phase) */
alpar@1:       int i, j;
alpar@1:       double *work;
alpar@1:       /* allocate and clear the working array */
alpar@1:       work = xcalloc(1+A->n, sizeof(double));
alpar@1:       for (j = 1; j <= A->n; j++)
alpar@1:          work[j] = 0.0;
alpar@1:       /* compute matrix C = A * B */
alpar@1:       for (i = 1; i <= C->m; i++)
alpar@1:       {  SPME *e, *ee;
alpar@1:          double temp;
alpar@1:          /* work := (i-th row of A) */
alpar@1:          /* (note that A may have duplicate elements) */
alpar@1:          for (e = A->row[i]; e != NULL; e = e->r_next)
alpar@1:             work[e->j] += e->val;
alpar@1:          /* compute i-th row of C */
alpar@1:          for (e = C->row[i]; e != NULL; e = e->r_next)
alpar@1:          {  j = e->j;
alpar@1:             /* c[i,j] := work * (j-th column of B) */
alpar@1:             temp = 0.0;
alpar@1:             for (ee = B->col[j]; ee != NULL; ee = ee->c_next)
alpar@1:                temp += work[ee->i] * ee->val;
alpar@1:             e->val = temp;
alpar@1:          }
alpar@1:          /* reset the working array */
alpar@1:          for (e = A->row[i]; e != NULL; e = e->r_next)
alpar@1:             work[e->j] = 0.0;
alpar@1:       }
alpar@1:       /* check and deallocate the working array */
alpar@1:       for (j = 1; j <= A->n; j++)
alpar@1:          xassert(work[j] == 0.0);
alpar@1:       xfree(work);
alpar@1:       return;
alpar@1: }
alpar@1: 
alpar@1: SPM *spm_mul_mat(const SPM *A, const SPM *B)
alpar@1: {     /* multiply two sparse matrices (driver routine) */
alpar@1:       SPM *C;
alpar@1:       C = spm_mul_sym(A, B);
alpar@1:       spm_mul_num(C, A, B);
alpar@1:       return C;
alpar@1: }
alpar@1: 
alpar@1: PER *spm_create_per(int n)
alpar@1: {     /* create permutation matrix */
alpar@1:       PER *P;
alpar@1:       int k;
alpar@1:       xassert(n >= 0);
alpar@1:       P = xmalloc(sizeof(PER));
alpar@1:       P->n = n;
alpar@1:       P->row = xcalloc(1+n, sizeof(int));
alpar@1:       P->col = xcalloc(1+n, sizeof(int));
alpar@1:       /* initially it is identity matrix */
alpar@1:       for (k = 1; k <= n; k++)
alpar@1:          P->row[k] = P->col[k] = k;
alpar@1:       return P;
alpar@1: }
alpar@1: 
alpar@1: void spm_check_per(PER *P)
alpar@1: {     /* check permutation matrix for correctness */
alpar@1:       int i, j;
alpar@1:       xassert(P->n >= 0);
alpar@1:       for (i = 1; i <= P->n; i++)
alpar@1:       {  j = P->row[i];
alpar@1:          xassert(1 <= j && j <= P->n);
alpar@1:          xassert(P->col[j] == i);
alpar@1:       }
alpar@1:       return;
alpar@1: }
alpar@1: 
alpar@1: void spm_delete_per(PER *P)
alpar@1: {     /* delete permutation matrix */
alpar@1:       xfree(P->row);
alpar@1:       xfree(P->col);
alpar@1:       xfree(P);
alpar@1:       return;
alpar@1: }
alpar@1: 
alpar@1: /* eof */