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Diffstat (limited to 'eigen/Eigen/src/OrderingMethods/Eigen_Colamd.h')
| -rw-r--r-- | eigen/Eigen/src/OrderingMethods/Eigen_Colamd.h | 1843 |
1 files changed, 0 insertions, 1843 deletions
diff --git a/eigen/Eigen/src/OrderingMethods/Eigen_Colamd.h b/eigen/Eigen/src/OrderingMethods/Eigen_Colamd.h deleted file mode 100644 index da85b4d..0000000 --- a/eigen/Eigen/src/OrderingMethods/Eigen_Colamd.h +++ /dev/null @@ -1,1843 +0,0 @@ -// // This file is part of Eigen, a lightweight C++ template library -// for linear algebra. -// -// Copyright (C) 2012 Desire Nuentsa Wakam <desire.nuentsa_wakam@inria.fr> -// -// This Source Code Form is subject to the terms of the Mozilla -// Public License v. 2.0. If a copy of the MPL was not distributed -// with this file, You can obtain one at http://mozilla.org/MPL/2.0/. - -// This file is modified from the colamd/symamd library. The copyright is below - -// The authors of the code itself are Stefan I. Larimore and Timothy A. -// Davis (davis@cise.ufl.edu), University of Florida. The algorithm was -// developed in collaboration with John Gilbert, Xerox PARC, and Esmond -// Ng, Oak Ridge National Laboratory. -// -// Date: -// -// September 8, 2003. Version 2.3. -// -// Acknowledgements: -// -// This work was supported by the National Science Foundation, under -// grants DMS-9504974 and DMS-9803599. -// -// Notice: -// -// Copyright (c) 1998-2003 by the University of Florida. -// All Rights Reserved. -// -// THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY -// EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK. -// -// Permission is hereby granted to use, copy, modify, and/or distribute -// this program, provided that the Copyright, this License, and the -// Availability of the original version is retained on all copies and made -// accessible to the end-user of any code or package that includes COLAMD -// or any modified version of COLAMD. -// -// Availability: -// -// The colamd/symamd library is available at -// -// http://www.suitesparse.com - - -#ifndef EIGEN_COLAMD_H -#define EIGEN_COLAMD_H - -namespace internal { -/* Ensure that debugging is turned off: */ -#ifndef COLAMD_NDEBUG -#define COLAMD_NDEBUG -#endif /* NDEBUG */ -/* ========================================================================== */ -/* === Knob and statistics definitions ====================================== */ -/* ========================================================================== */ - -/* size of the knobs [ ] array. Only knobs [0..1] are currently used. */ -#define COLAMD_KNOBS 20 - -/* number of output statistics. Only stats [0..6] are currently used. */ -#define COLAMD_STATS 20 - -/* knobs [0] and stats [0]: dense row knob and output statistic. */ -#define COLAMD_DENSE_ROW 0 - -/* knobs [1] and stats [1]: dense column knob and output statistic. */ -#define COLAMD_DENSE_COL 1 - -/* stats [2]: memory defragmentation count output statistic */ -#define COLAMD_DEFRAG_COUNT 2 - -/* stats [3]: colamd status: zero OK, > 0 warning or notice, < 0 error */ -#define COLAMD_STATUS 3 - -/* stats [4..6]: error info, or info on jumbled columns */ -#define COLAMD_INFO1 4 -#define COLAMD_INFO2 5 -#define COLAMD_INFO3 6 - -/* error codes returned in stats [3]: */ -#define COLAMD_OK (0) -#define COLAMD_OK_BUT_JUMBLED (1) -#define COLAMD_ERROR_A_not_present (-1) -#define COLAMD_ERROR_p_not_present (-2) -#define COLAMD_ERROR_nrow_negative (-3) -#define COLAMD_ERROR_ncol_negative (-4) -#define COLAMD_ERROR_nnz_negative (-5) -#define COLAMD_ERROR_p0_nonzero (-6) -#define COLAMD_ERROR_A_too_small (-7) -#define COLAMD_ERROR_col_length_negative (-8) -#define COLAMD_ERROR_row_index_out_of_bounds (-9) -#define COLAMD_ERROR_out_of_memory (-10) -#define COLAMD_ERROR_internal_error (-999) - -/* ========================================================================== */ -/* === Definitions ========================================================== */ -/* ========================================================================== */ - -#define ONES_COMPLEMENT(r) (-(r)-1) - -/* -------------------------------------------------------------------------- */ - -#define COLAMD_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 =========================================== */ -/* ========================================================================== */ - -// == Row and Column structures == -template <typename IndexType> -struct colamd_col -{ - IndexType start ; /* index for A of first row in this column, or DEAD */ - /* if column is dead */ - IndexType length ; /* number of rows in this column */ - union - { - IndexType thickness ; /* number of original columns represented by this */ - /* col, if the column is alive */ - IndexType parent ; /* parent in parent tree super-column structure, if */ - /* the column is dead */ - } shared1 ; - union - { - IndexType score ; /* the score used to maintain heap, if col is alive */ - IndexType order ; /* pivot ordering of this column, if col is dead */ - } shared2 ; - union - { - IndexType headhash ; /* head of a hash bucket, if col is at the head of */ - /* a degree list */ - IndexType hash ; /* hash value, if col is not in a degree list */ - IndexType prev ; /* previous column in degree list, if col is in a */ - /* degree list (but not at the head of a degree list) */ - } shared3 ; - union - { - IndexType degree_next ; /* next column, if col is in a degree list */ - IndexType hash_next ; /* next column, if col is in a hash list */ - } shared4 ; - -}; - -template <typename IndexType> -struct Colamd_Row -{ - IndexType start ; /* index for A of first col in this row */ - IndexType length ; /* number of principal columns in this row */ - union - { - IndexType degree ; /* number of principal & non-principal columns in row */ - IndexType p ; /* used as a row pointer in init_rows_cols () */ - } shared1 ; - union - { - IndexType mark ; /* for computing set differences and marking dead rows*/ - IndexType first_column ;/* first column in row (used in garbage collection) */ - } shared2 ; - -}; - -/* ========================================================================== */ -/* === Colamd recommended memory size ======================================= */ -/* ========================================================================== */ - -/* - The recommended length Alen of the array A passed to colamd is given by - the COLAMD_RECOMMENDED (nnz, n_row, n_col) macro. It returns -1 if any - argument is negative. 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. An additional n_col space is the minimal amount of "elbow room", - and nnz/5 more space is recommended for run time efficiency. - - This macro is not needed when using symamd. - - Explicit typecast to IndexType added Sept. 23, 2002, COLAMD version 2.2, to avoid - gcc -pedantic warning messages. -*/ -template <typename IndexType> -inline IndexType colamd_c(IndexType n_col) -{ return IndexType( ((n_col) + 1) * sizeof (colamd_col<IndexType>) / sizeof (IndexType) ) ; } - -template <typename IndexType> -inline IndexType colamd_r(IndexType n_row) -{ return IndexType(((n_row) + 1) * sizeof (Colamd_Row<IndexType>) / sizeof (IndexType)); } - -// Prototypes of non-user callable routines -template <typename IndexType> -static IndexType init_rows_cols (IndexType n_row, IndexType n_col, Colamd_Row<IndexType> Row [], colamd_col<IndexType> col [], IndexType A [], IndexType p [], IndexType stats[COLAMD_STATS] ); - -template <typename IndexType> -static void init_scoring (IndexType n_row, IndexType n_col, Colamd_Row<IndexType> Row [], colamd_col<IndexType> Col [], IndexType A [], IndexType head [], double knobs[COLAMD_KNOBS], IndexType *p_n_row2, IndexType *p_n_col2, IndexType *p_max_deg); - -template <typename IndexType> -static IndexType find_ordering (IndexType n_row, IndexType n_col, IndexType Alen, Colamd_Row<IndexType> Row [], colamd_col<IndexType> Col [], IndexType A [], IndexType head [], IndexType n_col2, IndexType max_deg, IndexType pfree); - -template <typename IndexType> -static void order_children (IndexType n_col, colamd_col<IndexType> Col [], IndexType p []); - -template <typename IndexType> -static void detect_super_cols (colamd_col<IndexType> Col [], IndexType A [], IndexType head [], IndexType row_start, IndexType row_length ) ; - -template <typename IndexType> -static IndexType garbage_collection (IndexType n_row, IndexType n_col, Colamd_Row<IndexType> Row [], colamd_col<IndexType> Col [], IndexType A [], IndexType *pfree) ; - -template <typename IndexType> -static inline IndexType clear_mark (IndexType n_row, Colamd_Row<IndexType> Row [] ) ; - -/* === No debugging ========================================================= */ - -#define COLAMD_DEBUG0(params) ; -#define COLAMD_DEBUG1(params) ; -#define COLAMD_DEBUG2(params) ; -#define COLAMD_DEBUG3(params) ; -#define COLAMD_DEBUG4(params) ; - -#define COLAMD_ASSERT(expression) ((void) 0) - - -/** - * \brief Returns the recommended value of Alen - * - * Returns recommended value of Alen for use by colamd. - * Returns -1 if any input argument is negative. - * The use of this routine or macro is optional. - * Note that the macro uses its arguments more than once, - * so be careful for side effects, if you pass expressions as arguments to COLAMD_RECOMMENDED. - * - * \param nnz nonzeros in A - * \param n_row number of rows in A - * \param n_col number of columns in A - * \return recommended value of Alen for use by colamd - */ -template <typename IndexType> -inline IndexType colamd_recommended ( IndexType nnz, IndexType n_row, IndexType n_col) -{ - if ((nnz) < 0 || (n_row) < 0 || (n_col) < 0) - return (-1); - else - return (2 * (nnz) + colamd_c (n_col) + colamd_r (n_row) + (n_col) + ((nnz) / 5)); -} - -/** - * \brief set default parameters The use of this routine is optional. - * - * Colamd: rows with more than (knobs [COLAMD_DENSE_ROW] * n_col) - * entries are removed prior to ordering. Columns with more than - * (knobs [COLAMD_DENSE_COL] * n_row) entries are removed prior to - * ordering, and placed last in the output column 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 0.5. 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. - * - * \param knobs parameter settings for colamd - */ - -static inline void colamd_set_defaults(double knobs[COLAMD_KNOBS]) -{ - /* === 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] = 0.5 ; /* ignore rows over 50% dense */ - knobs [COLAMD_DENSE_COL] = 0.5 ; /* ignore columns over 50% dense */ -} - -/** - * \brief Computes a column ordering using the column approximate minimum degree ordering - * - * 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. - * - * - * \param n_row number of rows in A - * \param n_col number of columns in A - * \param Alen, size of the array A - * \param A row indices of the matrix, of size ALen - * \param p column pointers of A, of size n_col+1 - * \param knobs parameter settings for colamd - * \param stats colamd output statistics and error codes - */ -template <typename IndexType> -static bool colamd(IndexType n_row, IndexType n_col, IndexType Alen, IndexType *A, IndexType *p, double knobs[COLAMD_KNOBS], IndexType stats[COLAMD_STATS]) -{ - /* === Local variables ================================================== */ - - IndexType i ; /* loop index */ - IndexType nnz ; /* nonzeros in A */ - IndexType Row_size ; /* size of Row [], in integers */ - IndexType Col_size ; /* size of Col [], in integers */ - IndexType need ; /* minimum required length of A */ - Colamd_Row<IndexType> *Row ; /* pointer into A of Row [0..n_row] array */ - colamd_col<IndexType> *Col ; /* pointer into A of Col [0..n_col] array */ - IndexType n_col2 ; /* number of non-dense, non-empty columns */ - IndexType n_row2 ; /* number of non-dense, non-empty rows */ - IndexType ngarbage ; /* number of garbage collections performed */ - IndexType max_deg ; /* maximum row degree */ - double default_knobs [COLAMD_KNOBS] ; /* default knobs array */ - - - /* === Check the input arguments ======================================== */ - - if (!stats) - { - COLAMD_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 ; - COLAMD_DEBUG0 (("colamd: A not present\n")) ; - return (false) ; - } - - if (!p) /* p is not present */ - { - stats [COLAMD_STATUS] = COLAMD_ERROR_p_not_present ; - COLAMD_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 ; - COLAMD_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 ; - COLAMD_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 ; - COLAMD_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] ; - COLAMD_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 ; - } - - /* === Allocate the Row and Col arrays from array A ===================== */ - - Col_size = colamd_c (n_col) ; - Row_size = colamd_r (n_row) ; - need = 2*nnz + n_col + Col_size + Row_size ; - - if (need > Alen) - { - /* 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 ; - COLAMD_DEBUG0 (("colamd: Need Alen >= %d, given only Alen = %d\n", need,Alen)); - return (false) ; - } - - Alen -= Col_size + Row_size ; - Col = (colamd_col<IndexType> *) &A [Alen] ; - Row = (Colamd_Row<IndexType> *) &A [Alen + Col_size] ; - - /* === Construct the row and column data structures ===================== */ - - if (!Eigen::internal::init_rows_cols (n_row, n_col, Row, Col, A, p, stats)) - { - /* input matrix is invalid */ - COLAMD_DEBUG0 (("colamd: Matrix invalid\n")) ; - return (false) ; - } - - /* === Initialize scores, kill dense rows/columns ======================= */ - - Eigen::internal::init_scoring (n_row, n_col, Row, Col, A, p, knobs, - &n_row2, &n_col2, &max_deg) ; - - /* === Order the supercolumns =========================================== */ - - ngarbage = Eigen::internal::find_ordering (n_row, n_col, Alen, Row, Col, A, p, - n_col2, max_deg, 2*nnz) ; - - /* === Order the non-principal columns ================================== */ - - Eigen::internal::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 ; - COLAMD_DEBUG0 (("colamd: done.\n")) ; - return (true) ; -} - -/* ========================================================================== */ -/* === 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. -*/ -template <typename IndexType> -static IndexType init_rows_cols /* returns true if OK, or false otherwise */ - ( - /* === Parameters ======================================================= */ - - IndexType n_row, /* number of rows of A */ - IndexType n_col, /* number of columns of A */ - Colamd_Row<IndexType> Row [], /* of size n_row+1 */ - colamd_col<IndexType> Col [], /* of size n_col+1 */ - IndexType A [], /* row indices of A, of size Alen */ - IndexType p [], /* pointers to columns in A, of size n_col+1 */ - IndexType stats [COLAMD_STATS] /* colamd statistics */ - ) -{ - /* === Local variables ================================================== */ - - IndexType col ; /* a column index */ - IndexType row ; /* a row index */ - IndexType *cp ; /* a column pointer */ - IndexType *cp_end ; /* a pointer to the end of a column */ - IndexType *rp ; /* a row pointer */ - IndexType *rp_end ; /* a pointer to the end of a row */ - IndexType 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) // extra parentheses to work-around gcc bug 10200 - { - /* column pointers must be non-decreasing */ - stats [COLAMD_STATUS] = COLAMD_ERROR_col_length_negative ; - stats [COLAMD_INFO1] = col ; - stats [COLAMD_INFO2] = Col [col].length ; - COLAMD_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 = COLAMD_EMPTY ; - Col [col].shared4.degree_next = COLAMD_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 ; - COLAMD_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]) ++ ; - COLAMD_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) - { - COLAMD_DEBUG0 (("colamd: reconstructing column form, matrix jumbled\n")) ; - - - /* === 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. -*/ -template <typename IndexType> -static void init_scoring - ( - /* === Parameters ======================================================= */ - - IndexType n_row, /* number of rows of A */ - IndexType n_col, /* number of columns of A */ - Colamd_Row<IndexType> Row [], /* of size n_row+1 */ - colamd_col<IndexType> Col [], /* of size n_col+1 */ - IndexType A [], /* column form and row form of A */ - IndexType head [], /* of size n_col+1 */ - double knobs [COLAMD_KNOBS],/* parameters */ - IndexType *p_n_row2, /* number of non-dense, non-empty rows */ - IndexType *p_n_col2, /* number of non-dense, non-empty columns */ - IndexType *p_max_deg /* maximum row degree */ - ) -{ - /* === Local variables ================================================== */ - - IndexType c ; /* a column index */ - IndexType r, row ; /* a row index */ - IndexType *cp ; /* a column pointer */ - IndexType deg ; /* degree of a row or column */ - IndexType *cp_end ; /* a pointer to the end of a column */ - IndexType *new_cp ; /* new column pointer */ - IndexType col_length ; /* length of pruned column */ - IndexType score ; /* current column score */ - IndexType n_col2 ; /* number of non-dense, non-empty columns */ - IndexType n_row2 ; /* number of non-dense, non-empty rows */ - IndexType dense_row_count ; /* remove rows with more entries than this */ - IndexType dense_col_count ; /* remove cols with more entries than this */ - IndexType min_score ; /* smallest column score */ - IndexType max_deg ; /* maximum row degree */ - IndexType next_col ; /* Used to add to degree list.*/ - - - /* === Extract knobs ==================================================== */ - - dense_row_count = numext::maxi(IndexType(0), numext::mini(IndexType(knobs [COLAMD_DENSE_ROW] * n_col), n_col)) ; - dense_col_count = numext::maxi(IndexType(0), numext::mini(IndexType(knobs [COLAMD_DENSE_COL] * n_row), n_row)) ; - COLAMD_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) ; - } - } - COLAMD_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) ; - } - } - COLAMD_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 ; - COLAMD_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 = numext::maxi(max_deg, deg) ; - } - } - COLAMD_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 = numext::mini(score, n_col) ; - } - /* determine pruned column length */ - col_length = (IndexType) (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) */ - COLAMD_DEBUG2 (("Newly null killed: %d\n", c)) ; - Col [c].shared2.order = --n_col2 ; - KILL_PRINCIPAL_COL (c) ; - } - else - { - /* set column length and set score */ - COLAMD_ASSERT (score >= 0) ; - COLAMD_ASSERT (score <= n_col) ; - Col [c].length = col_length ; - Col [c].shared2.score = score ; - } - } - COLAMD_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. */ - - /* === Initialize degree lists ========================================== */ - - - /* clear the hash buckets */ - for (c = 0 ; c <= n_col ; c++) - { - head [c] = COLAMD_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)) - { - COLAMD_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 ; - - COLAMD_ASSERT (min_score >= 0) ; - COLAMD_ASSERT (min_score <= n_col) ; - COLAMD_ASSERT (score >= 0) ; - COLAMD_ASSERT (score <= n_col) ; - COLAMD_ASSERT (head [score] >= COLAMD_EMPTY) ; - - /* now add this column to dList at proper score location */ - next_col = head [score] ; - Col [c].shared3.prev = COLAMD_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 != COLAMD_EMPTY) - { - Col [next_col].shared3.prev = c ; - } - head [score] = c ; - - /* see if this score is less than current min */ - min_score = numext::mini(min_score, score) ; - - - } - } - - - /* === 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. -*/ -template <typename IndexType> -static IndexType find_ordering /* return the number of garbage collections */ - ( - /* === Parameters ======================================================= */ - - IndexType n_row, /* number of rows of A */ - IndexType n_col, /* number of columns of A */ - IndexType Alen, /* size of A, 2*nnz + n_col or larger */ - Colamd_Row<IndexType> Row [], /* of size n_row+1 */ - colamd_col<IndexType> Col [], /* of size n_col+1 */ - IndexType A [], /* column form and row form of A */ - IndexType head [], /* of size n_col+1 */ - IndexType n_col2, /* Remaining columns to order */ - IndexType max_deg, /* Maximum row degree */ - IndexType pfree /* index of first free slot (2*nnz on entry) */ - ) -{ - /* === Local variables ================================================== */ - - IndexType k ; /* current pivot ordering step */ - IndexType pivot_col ; /* current pivot column */ - IndexType *cp ; /* a column pointer */ - IndexType *rp ; /* a row pointer */ - IndexType pivot_row ; /* current pivot row */ - IndexType *new_cp ; /* modified column pointer */ - IndexType *new_rp ; /* modified row pointer */ - IndexType pivot_row_start ; /* pointer to start of pivot row */ - IndexType pivot_row_degree ; /* number of columns in pivot row */ - IndexType pivot_row_length ; /* number of supercolumns in pivot row */ - IndexType pivot_col_score ; /* score of pivot column */ - IndexType needed_memory ; /* free space needed for pivot row */ - IndexType *cp_end ; /* pointer to the end of a column */ - IndexType *rp_end ; /* pointer to the end of a row */ - IndexType row ; /* a row index */ - IndexType col ; /* a column index */ - IndexType max_score ; /* maximum possible score */ - IndexType cur_score ; /* score of current column */ - unsigned int hash ; /* hash value for supernode detection */ - IndexType head_column ; /* head of hash bucket */ - IndexType first_col ; /* first column in hash bucket */ - IndexType tag_mark ; /* marker value for mark array */ - IndexType row_mark ; /* Row [row].shared2.mark */ - IndexType set_difference ; /* set difference size of row with pivot row */ - IndexType min_score ; /* smallest column score */ - IndexType col_thickness ; /* "thickness" (no. of columns in a supercol) */ - IndexType max_mark ; /* maximum value of tag_mark */ - IndexType pivot_col_thickness ; /* number of columns represented by pivot col */ - IndexType prev_col ; /* Used by Dlist operations. */ - IndexType next_col ; /* Used by Dlist operations. */ - IndexType ngarbage ; /* number of garbage collections performed */ - - - /* === Initialization and clear mark ==================================== */ - - max_mark = INT_MAX - n_col ; /* INT_MAX defined in <limits.h> */ - tag_mark = Eigen::internal::clear_mark (n_row, Row) ; - min_score = 0 ; - ngarbage = 0 ; - COLAMD_DEBUG1 (("colamd: Ordering, n_col2=%d\n", n_col2)) ; - - /* === Order the columns ================================================ */ - - for (k = 0 ; k < n_col2 ; /* 'k' is incremented below */) - { - - /* === Select pivot column, and order it ============================ */ - - /* make sure degree list isn't empty */ - COLAMD_ASSERT (min_score >= 0) ; - COLAMD_ASSERT (min_score <= n_col) ; - COLAMD_ASSERT (head [min_score] >= COLAMD_EMPTY) ; - - /* get pivot column from head of minimum degree list */ - while (min_score < n_col && head [min_score] == COLAMD_EMPTY) - { - min_score++ ; - } - pivot_col = head [min_score] ; - COLAMD_ASSERT (pivot_col >= 0 && pivot_col <= n_col) ; - next_col = Col [pivot_col].shared4.degree_next ; - head [min_score] = next_col ; - if (next_col != COLAMD_EMPTY) - { - Col [next_col].shared3.prev = COLAMD_EMPTY ; - } - - COLAMD_ASSERT (COL_IS_ALIVE (pivot_col)) ; - COLAMD_DEBUG3 (("Pivot col: %d\n", 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 ; - COLAMD_ASSERT (pivot_col_thickness > 0) ; - - /* === Garbage_collection, if necessary ============================= */ - - needed_memory = numext::mini(pivot_col_score, n_col - k) ; - if (pfree + needed_memory >= Alen) - { - pfree = Eigen::internal::garbage_collection (n_row, n_col, Row, Col, A, &A [pfree]) ; - ngarbage++ ; - /* after garbage collection we will have enough */ - COLAMD_ASSERT (pfree + needed_memory < Alen) ; - /* garbage collection has wiped out the Row[].shared2.mark array */ - tag_mark = Eigen::internal::clear_mark (n_row, Row) ; - - } - - /* === 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++ ; - COLAMD_DEBUG4 (("Pivot col pattern %d %d\n", ROW_IS_ALIVE (row), row)) ; - /* skip if row is dead */ - if (ROW_IS_DEAD (row)) - { - continue ; - } - 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 ; - COLAMD_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 = numext::maxi(max_deg, pivot_row_degree) ; - - - /* === 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++ ; - COLAMD_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] ; - COLAMD_DEBUG3 (("Pivotal row is %d\n", pivot_row)) ; - } - else - { - /* there is no pivot row, since it is of zero length */ - pivot_row = COLAMD_EMPTY ; - COLAMD_ASSERT (pivot_row_length == 0) ; - } - COLAMD_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 ====================================== */ - - COLAMD_DEBUG3 (("** Computing set differences phase. **\n")) ; - - /* pivot row is currently dead - it will be revived later. */ - - COLAMD_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++ ; - COLAMD_ASSERT (COL_IS_ALIVE (col) && col != pivot_col) ; - COLAMD_DEBUG3 (("Col: %d\n", col)) ; - - /* clear tags used to construct pivot row pattern */ - col_thickness = -Col [col].shared1.thickness ; - COLAMD_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 ; - COLAMD_ASSERT (cur_score >= 0) ; - COLAMD_ASSERT (cur_score <= n_col) ; - COLAMD_ASSERT (cur_score >= COLAMD_EMPTY) ; - if (prev_col == COLAMD_EMPTY) - { - head [cur_score] = next_col ; - } - else - { - Col [prev_col].shared4.degree_next = next_col ; - } - if (next_col != COLAMD_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 ; - } - COLAMD_ASSERT (row != pivot_row) ; - set_difference = row_mark - tag_mark ; - /* check if the row has been seen yet */ - if (set_difference < 0) - { - COLAMD_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 ; - COLAMD_ASSERT (set_difference >= 0) ; - /* absorb this row if the set difference becomes zero */ - if (set_difference == 0) - { - COLAMD_DEBUG3 (("aggressive absorption. Row: %d\n", row)) ; - KILL_ROW (row) ; - } - else - { - /* save the new mark */ - Row [row].shared2.mark = set_difference + tag_mark ; - } - } - } - - - /* === Add up set differences for each column ======================= */ - - COLAMD_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++ ; - COLAMD_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 ; - - COLAMD_DEBUG4 (("Adding set diffs for Col: %d.\n", col)) ; - - while (cp < cp_end) - { - /* get a row */ - row = *cp++ ; - COLAMD_ASSERT(row >= 0 && row < n_row) ; - row_mark = Row [row].shared2.mark ; - /* skip if dead */ - if (ROW_IS_MARKED_DEAD (row_mark)) - { - continue ; - } - COLAMD_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 = numext::mini(cur_score, n_col) ; - } - - /* recompute the column's length */ - Col [col].length = (IndexType) (new_cp - &A [Col [col].start]) ; - - /* === Further mass elimination ================================= */ - - if (Col [col].length == 0) - { - COLAMD_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 ; - COLAMD_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 ==================== */ - - COLAMD_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 ; - - COLAMD_DEBUG4 ((" Hash = %d, n_col = %d.\n", hash, n_col)) ; - COLAMD_ASSERT (hash <= n_col) ; - - head_column = head [hash] ; - if (head_column > COLAMD_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 = (IndexType) hash ; - COLAMD_ASSERT (COL_IS_ALIVE (col)) ; - } - } - - /* The approximate external column degree is now computed. */ - - /* === Supercolumn detection ======================================== */ - - COLAMD_DEBUG3 (("** Supercolumn detection phase. **\n")) ; - - Eigen::internal::detect_super_cols (Col, A, head, pivot_row_start, pivot_row_length) ; - - /* === Kill the pivotal column ====================================== */ - - KILL_PRINCIPAL_COL (pivot_col) ; - - /* === Clear mark =================================================== */ - - tag_mark += (max_deg + 1) ; - if (tag_mark >= max_mark) - { - COLAMD_DEBUG2 (("clearing tag_mark\n")) ; - tag_mark = Eigen::internal::clear_mark (n_row, Row) ; - } - - /* === Finalize the new pivot row, and column scores ================ */ - - COLAMD_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 = numext::mini(cur_score, max_score) ; - COLAMD_ASSERT (cur_score >= 0) ; - - /* store updated score */ - Col [col].shared2.score = cur_score ; - - /* === Place column back in degree list ========================= */ - - COLAMD_ASSERT (min_score >= 0) ; - COLAMD_ASSERT (min_score <= n_col) ; - COLAMD_ASSERT (cur_score >= 0) ; - COLAMD_ASSERT (cur_score <= n_col) ; - COLAMD_ASSERT (head [cur_score] >= COLAMD_EMPTY) ; - next_col = head [cur_score] ; - Col [col].shared4.degree_next = next_col ; - Col [col].shared3.prev = COLAMD_EMPTY ; - if (next_col != COLAMD_EMPTY) - { - Col [next_col].shared3.prev = col ; - } - head [cur_score] = col ; - - /* see if this score is less than current min */ - min_score = numext::mini(min_score, cur_score) ; - - } - - /* === 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 = (IndexType) (new_rp - &A[pivot_row_start]) ; - Row [pivot_row].shared1.degree = pivot_row_degree ; - Row [pivot_row].shared2.mark = 0 ; - /* pivot row is no longer dead */ - } - } - - /* === 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. -*/ -template <typename IndexType> -static inline void order_children -( - /* === Parameters ======================================================= */ - - IndexType n_col, /* number of columns of A */ - colamd_col<IndexType> Col [], /* of size n_col+1 */ - IndexType p [] /* p [0 ... n_col-1] is the column permutation*/ - ) -{ - /* === Local variables ================================================== */ - - IndexType i ; /* loop counter for all columns */ - IndexType c ; /* column index */ - IndexType parent ; /* index of column's parent */ - IndexType order ; /* column's order */ - - /* === Order each non-principal column ================================== */ - - for (i = 0 ; i < n_col ; i++) - { - /* find an un-ordered non-principal column */ - COLAMD_ASSERT (COL_IS_DEAD (i)) ; - if (!COL_IS_DEAD_PRINCIPAL (i) && Col [i].shared2.order == COLAMD_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 - { - COLAMD_ASSERT (Col [c].shared2.order == COLAMD_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 == COLAMD_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. -*/ -template <typename IndexType> -static void detect_super_cols -( - /* === Parameters ======================================================= */ - - colamd_col<IndexType> Col [], /* of size n_col+1 */ - IndexType A [], /* row indices of A */ - IndexType head [], /* head of degree lists and hash buckets */ - IndexType row_start, /* pointer to set of columns to check */ - IndexType row_length /* number of columns to check */ -) -{ - /* === Local variables ================================================== */ - - IndexType hash ; /* hash value for a column */ - IndexType *rp ; /* pointer to a row */ - IndexType c ; /* a column index */ - IndexType super_c ; /* column index of the column to absorb into */ - IndexType *cp1 ; /* column pointer for column super_c */ - IndexType *cp2 ; /* column pointer for column c */ - IndexType length ; /* length of column super_c */ - IndexType prev_c ; /* column preceding c in hash bucket */ - IndexType i ; /* loop counter */ - IndexType *rp_end ; /* pointer to the end of the row */ - IndexType col ; /* a column index in the row to check */ - IndexType head_column ; /* first column in hash bucket or degree list */ - IndexType 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 ; - COLAMD_ASSERT (hash <= n_col) ; - - /* === Get the first column in this hash bucket ===================== */ - - head_column = head [hash] ; - if (head_column > COLAMD_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 != COLAMD_EMPTY ; - super_c = Col [super_c].shared4.hash_next) - { - COLAMD_ASSERT (COL_IS_ALIVE (super_c)) ; - COLAMD_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 != COLAMD_EMPTY ; c = Col [c].shared4.hash_next) - { - COLAMD_ASSERT (c != super_c) ; - COLAMD_ASSERT (COL_IS_ALIVE (c)) ; - COLAMD_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) */ - COLAMD_ASSERT (ROW_IS_ALIVE (*cp1)) ; - COLAMD_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 =================== */ - - COLAMD_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 = COLAMD_EMPTY ; - /* remove c from hash bucket */ - Col [prev_c].shared4.hash_next = Col [c].shared4.hash_next ; - } - } - - /* === Empty this hash bucket ======================================= */ - - if (head_column > COLAMD_EMPTY) - { - /* corresponding degree list "hash" is not empty */ - Col [head_column].shared3.headhash = COLAMD_EMPTY ; - } - else - { - /* corresponding degree list "hash" is empty */ - head [hash] = COLAMD_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. -*/ -template <typename IndexType> -static IndexType garbage_collection /* returns the new value of pfree */ - ( - /* === Parameters ======================================================= */ - - IndexType n_row, /* number of rows */ - IndexType n_col, /* number of columns */ - Colamd_Row<IndexType> Row [], /* row info */ - colamd_col<IndexType> Col [], /* column info */ - IndexType A [], /* A [0 ... Alen-1] holds the matrix */ - IndexType *pfree /* &A [0] ... pfree is in use */ - ) -{ - /* === Local variables ================================================== */ - - IndexType *psrc ; /* source pointer */ - IndexType *pdest ; /* destination pointer */ - IndexType j ; /* counter */ - IndexType r ; /* a row index */ - IndexType c ; /* a column index */ - IndexType length ; /* length of a row or column */ - - /* === 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 */ - COLAMD_ASSERT (pdest <= psrc) ; - Col [c].start = (IndexType) (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 = (IndexType) (pdest - &A [Col [c].start]) ; - } - } - - /* === Prepare to defragment the rows =================================== */ - - for (r = 0 ; r < n_row ; r++) - { - if (ROW_IS_ALIVE (r)) - { - if (Row [r].length == 0) - { - /* this row is of zero length. cannot compact it, so kill it */ - COLAMD_DEBUG3 (("Defrag row kill\n")) ; - 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 ; - COLAMD_ASSERT (ROW_IS_ALIVE (r)) ; - /* flag the start of the row with the one's complement of row */ - *psrc = ONES_COMPLEMENT (r) ; - - } - } - } - - /* === 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) ; - COLAMD_ASSERT (r >= 0 && r < n_row) ; - /* restore first column index */ - *psrc = Row [r].shared2.first_column ; - COLAMD_ASSERT (ROW_IS_ALIVE (r)) ; - - /* move and compact the row */ - COLAMD_ASSERT (pdest <= psrc) ; - Row [r].start = (IndexType) (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 = (IndexType) (pdest - &A [Row [r].start]) ; - - } - } - /* ensure we found all the rows */ - COLAMD_ASSERT (debug_rows == 0) ; - - /* === Return the new value of pfree ==================================== */ - - return ((IndexType) (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. -*/ -template <typename IndexType> -static inline IndexType clear_mark /* return the new value for tag_mark */ - ( - /* === Parameters ======================================================= */ - - IndexType n_row, /* number of rows in A */ - Colamd_Row<IndexType> Row [] /* Row [0 ... n_row-1].shared2.mark is set to zero */ - ) -{ - /* === Local variables ================================================== */ - - IndexType r ; - - for (r = 0 ; r < n_row ; r++) - { - if (ROW_IS_ALIVE (r)) - { - Row [r].shared2.mark = 0 ; - } - } - return (1) ; -} - - -} // namespace internal -#endif |