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/* ========================================================================== */
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/* === colamd mexFunction =================================================== */
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/* ========================================================================== */
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[ P, stats ] = colamd (A, knobs) ;
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see colamd.m for a description.
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The authors of the code itself are Stefan I. Larimore and Timothy A.
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Davis (davis at cise.ufl.edu), University of Florida. The algorithm was
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developed in collaboration with John Gilbert, Xerox PARC, and Esmond
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Ng, Oak Ridge National Laboratory.
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This work was supported by the National Science Foundation, under
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grants DMS-9504974 and DMS-9803599.
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Copyright (c) 1998-2006, Timothy A. Davis, All Rights Reserved.
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See http://www.cise.ufl.edu/research/sparse/colamd (the colamd.c
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file) for the License.
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The colamd/symamd library is available at
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http://www.cise.ufl.edu/research/sparse/colamd/
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This is the http://www.cise.ufl.edu/research/sparse/colamd/colamdmex.c
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file. It requires the colamd.c and colamd.h files.
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/* ========================================================================== */
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/* === Include files ======================================================== */
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/* ========================================================================== */
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/* ========================================================================== */
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/* === colamd mexFunction =================================================== */
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/* ========================================================================== */
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/* === Parameters ======================================================= */
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int nlhs, /* number of left-hand sides */
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mxArray *plhs [], /* left-hand side matrices */
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int nrhs, /* number of right--hand sides */
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const mxArray *prhs [] /* right-hand side matrices */
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/* === Local variables ================================================== */
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int *A ; /* colamd's copy of the matrix, and workspace */
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int *p ; /* colamd's copy of the column pointers */
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int Alen ; /* size of A */
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int n_col ; /* number of columns of A */
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int n_row ; /* number of rows of A */
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int nnz ; /* number of entries in A */
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int full ; /* TRUE if input matrix full, FALSE if sparse */
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double knobs [COLAMD_KNOBS] ; /* colamd user-controllable parameters */
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double *out_perm ; /* output permutation vector */
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double *out_stats ; /* output stats vector */
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double *in_knobs ; /* input knobs vector */
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int i ; /* loop counter */
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mxArray *Ainput ; /* input matrix handle */
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int spumoni ; /* verbosity variable */
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int stats [COLAMD_STATS] ; /* stats for colamd */
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colamd_printf = mexPrintf ; /* COLAMD printf routine */
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/* === Check inputs ===================================================== */
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if (nrhs < 1 || nrhs > 2 || nlhs < 0 || nlhs > 2)
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"colamd: incorrect number of input and/or output arguments") ;
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/* === Get knobs ======================================================== */
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colamd_set_defaults (knobs) ;
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/* check for user-passed knobs */
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in_knobs = mxGetPr (prhs [1]) ;
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i = mxGetNumberOfElements (prhs [1]) ;
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if (i > 0) knobs [COLAMD_DENSE_ROW] = in_knobs [0] ;
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if (i > 1) knobs [COLAMD_DENSE_COL] = in_knobs [1] ;
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if (i > 2) spumoni = (int) (in_knobs [2] != 0) ;
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/* print knob settings if spumoni is set */
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mexPrintf ("\ncolamd version %d.%d, %s:\n",
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COLAMD_MAIN_VERSION, COLAMD_SUB_VERSION, COLAMD_DATE) ;
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if (knobs [COLAMD_DENSE_ROW] >= 0)
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mexPrintf ("knobs(1): %g, rows with > max(16,%g*sqrt(size(A,2)))"
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" entries removed\n", in_knobs [0], knobs [COLAMD_DENSE_ROW]) ;
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mexPrintf ("knobs(1): %g, only completely dense rows removed\n",
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if (knobs [COLAMD_DENSE_COL] >= 0)
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mexPrintf ("knobs(2): %g, cols with > max(16,%g*sqrt(min(size(A)))"
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" entries removed\n", in_knobs [1], knobs [COLAMD_DENSE_COL]) ;
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mexPrintf ("knobs(2): %g, only completely dense columns removed\n",
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mexPrintf ("knobs(3): %g, statistics and knobs printed\n",
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/* === If A is full, convert to a sparse matrix ========================= */
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Ainput = (mxArray *) prhs [0] ;
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if (mxGetNumberOfDimensions (Ainput) != 2)
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mexErrMsgTxt ("colamd: input matrix must be 2-dimensional") ;
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full = !mxIsSparse (Ainput) ;
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mexCallMATLAB (1, &Ainput, 1, (mxArray **) prhs, "sparse") ;
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/* === Allocate workspace for colamd ==================================== */
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/* get size of matrix */
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n_row = mxGetM (Ainput) ;
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n_col = mxGetN (Ainput) ;
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/* get column pointer vector so we can find nnz */
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p = (int *) mxCalloc (n_col+1, sizeof (int)) ;
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(void) memcpy (p, mxGetJc (Ainput), (n_col+1)*sizeof (int)) ;
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Alen = (int) colamd_recommended (nnz, n_row, n_col) ;
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mexErrMsgTxt ("colamd: problem too large") ;
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/* === Copy input matrix into workspace ================================= */
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A = (int *) mxCalloc (Alen, sizeof (int)) ;
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(void) memcpy (A, mxGetIr (Ainput), nnz*sizeof (int)) ;
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mxDestroyArray (Ainput) ;
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/* === Order the columns (destroys A) =================================== */
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if (!colamd (n_row, n_col, Alen, A, p, knobs, stats))
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colamd_report (stats) ;
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mexErrMsgTxt ("colamd error!") ;
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/* === Return the permutation vector ==================================== */
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plhs [0] = mxCreateDoubleMatrix (1, n_col, mxREAL) ;
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out_perm = mxGetPr (plhs [0]) ;
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for (i = 0 ; i < n_col ; i++)
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/* colamd is 0-based, but MATLAB expects this to be 1-based */
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out_perm [i] = p [i] + 1 ;
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/* === Return the stats vector ========================================== */
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/* print stats if spumoni is set */
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colamd_report (stats) ;
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plhs [1] = mxCreateDoubleMatrix (1, COLAMD_STATS, mxREAL) ;
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out_stats = mxGetPr (plhs [1]) ;
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for (i = 0 ; i < COLAMD_STATS ; i++)
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out_stats [i] = stats [i] ;
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/* fix stats (5) and (6), for 1-based information on jumbled matrix. */
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/* note that this correction doesn't occur if symamd returns FALSE */
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out_stats [COLAMD_INFO1] ++ ;
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out_stats [COLAMD_INFO2] ++ ;
added
removed
COLAMD/colamdmex.c
