[9] | 1 | /* ========================================================================= */ |
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| 2 | /* === AMD_valid =========================================================== */ |
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| 3 | /* ========================================================================= */ |
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| 4 | |
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| 5 | /* ------------------------------------------------------------------------- */ |
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| 6 | /* AMD, Copyright (c) Timothy A. Davis, */ |
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| 7 | /* Patrick R. Amestoy, and Iain S. Duff. See ../README.txt for License. */ |
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| 8 | /* email: davis at cise.ufl.edu CISE Department, Univ. of Florida. */ |
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| 9 | /* web: http://www.cise.ufl.edu/research/sparse/amd */ |
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| 10 | /* ------------------------------------------------------------------------- */ |
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| 11 | |
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| 12 | /* Check if a column-form matrix is valid or not. The matrix A is |
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| 13 | * n_row-by-n_col. The row indices of entries in column j are in |
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| 14 | * Ai [Ap [j] ... Ap [j+1]-1]. Required conditions are: |
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| 15 | * |
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| 16 | * n_row >= 0 |
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| 17 | * n_col >= 0 |
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| 18 | * nz = Ap [n_col] >= 0 number of entries in the matrix |
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| 19 | * Ap [0] == 0 |
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| 20 | * Ap [j] <= Ap [j+1] for all j in the range 0 to n_col. |
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| 21 | * Ai [0 ... nz-1] must be in the range 0 to n_row-1. |
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| 22 | * |
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| 23 | * If any of the above conditions hold, AMD_INVALID is returned. If the |
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| 24 | * following condition holds, AMD_OK_BUT_JUMBLED is returned (a warning, |
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| 25 | * not an error): |
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| 26 | * |
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| 27 | * row indices in Ai [Ap [j] ... Ap [j+1]-1] are not sorted in ascending |
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| 28 | * order, and/or duplicate entries exist. |
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| 29 | * |
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| 30 | * Otherwise, AMD_OK is returned. |
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| 31 | * |
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| 32 | * In v1.2 and earlier, this function returned TRUE if the matrix was valid |
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| 33 | * (now returns AMD_OK), or FALSE otherwise (now returns AMD_INVALID or |
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| 34 | * AMD_OK_BUT_JUMBLED). |
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| 35 | */ |
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| 36 | |
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| 37 | #include "amd_internal.h" |
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| 38 | |
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| 39 | GLOBAL Int AMD_valid |
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| 40 | ( |
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| 41 | /* inputs, not modified on output: */ |
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| 42 | Int n_row, /* A is n_row-by-n_col */ |
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| 43 | Int n_col, |
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| 44 | const Int Ap [ ], /* column pointers of A, of size n_col+1 */ |
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| 45 | const Int Ai [ ] /* row indices of A, of size nz = Ap [n_col] */ |
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| 46 | ) |
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| 47 | { |
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| 48 | Int nz, j, p1, p2, ilast, i, p, result = AMD_OK ; |
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| 49 | |
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| 50 | if (n_row < 0 || n_col < 0 || Ap == NULL || Ai == NULL) |
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| 51 | { |
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| 52 | return (AMD_INVALID) ; |
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| 53 | } |
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| 54 | nz = Ap [n_col] ; |
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| 55 | if (Ap [0] != 0 || nz < 0) |
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| 56 | { |
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| 57 | /* column pointers must start at Ap [0] = 0, and Ap [n] must be >= 0 */ |
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| 58 | AMD_DEBUG0 (("column 0 pointer bad or nz < 0\n")) ; |
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| 59 | return (AMD_INVALID) ; |
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| 60 | } |
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| 61 | for (j = 0 ; j < n_col ; j++) |
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| 62 | { |
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| 63 | p1 = Ap [j] ; |
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| 64 | p2 = Ap [j+1] ; |
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| 65 | AMD_DEBUG2 (("\nColumn: "ID" p1: "ID" p2: "ID"\n", j, p1, p2)) ; |
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| 66 | if (p1 > p2) |
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| 67 | { |
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| 68 | /* column pointers must be ascending */ |
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| 69 | AMD_DEBUG0 (("column "ID" pointer bad\n", j)) ; |
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| 70 | return (AMD_INVALID) ; |
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| 71 | } |
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| 72 | ilast = EMPTY ; |
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| 73 | for (p = p1 ; p < p2 ; p++) |
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| 74 | { |
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| 75 | i = Ai [p] ; |
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| 76 | AMD_DEBUG3 (("row: "ID"\n", i)) ; |
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| 77 | if (i < 0 || i >= n_row) |
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| 78 | { |
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| 79 | /* row index out of range */ |
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| 80 | AMD_DEBUG0 (("index out of range, col "ID" row "ID"\n", j, i)); |
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| 81 | return (AMD_INVALID) ; |
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| 82 | } |
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| 83 | if (i <= ilast) |
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| 84 | { |
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| 85 | /* row index unsorted, or duplicate entry present */ |
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| 86 | AMD_DEBUG1 (("index unsorted/dupl col "ID" row "ID"\n", j, i)); |
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| 87 | result = AMD_OK_BUT_JUMBLED ; |
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| 88 | } |
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| 89 | ilast = i ; |
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| 90 | } |
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| 91 | } |
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| 92 | return (result) ; |
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| 93 | } |
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