1 #include "cs_mex.h"
2 /* cs_sqr: symbolic sparse QR factorization */
mexFunction(int nargout,mxArray * pargout[],int nargin,const mxArray * pargin[])3 void mexFunction
4 (
5 int nargout,
6 mxArray *pargout [ ],
7 int nargin,
8 const mxArray *pargin [ ]
9 )
10 {
11 double s ;
12 cs_dls *S ;
13 cs_dl Amatrix, *A ;
14 CS_INT m, n, order, *p ;
15 if (nargout > 7 || nargin != 1)
16 {
17 mexErrMsgTxt ("Usage: [vnz,rnz,parent,c,leftmost,p,q] = cs_sqr(A)") ;
18 }
19 A = cs_dl_mex_get_sparse (&Amatrix, 0, 1, pargin [0]) ; /* get A */
20 m = A->m ;
21 n = A->n ;
22 if (m < n) mexErrMsgTxt ("A must have # rows >= # columns") ;
23 order = (nargout == 7) ? 3 : 0 ; /* determine ordering */
24 S = cs_dl_sqr (order, A, 1) ; /* symbolic QR ordering & analysis*/
25 if (!S) mexErrMsgTxt ("cs_sqr failed") ;
26 s = S->lnz ;
27 cs_dl_mex_put_double (1, &s, &(pargout [0])) ; /* return nnz(V) */
28 s = S->unz ;
29 cs_dl_mex_put_double (1, &s, &(pargout [1])) ; /* return nnz(R) */
30 pargout [2] = cs_dl_mex_put_int (S->parent, n, 1, 0) ; /* return parent */
31 pargout [3] = cs_dl_mex_put_int (S->cp, n, 0, 0) ; /* return c */
32 pargout [4] = cs_dl_mex_put_int (S->leftmost, m, 1, 0) ;/* return leftmost*/
33 p = cs_dl_pinv (S->pinv, S->m2) ; /* p = pinv' */
34 pargout [5] = cs_dl_mex_put_int (p, S->m2, 1, 1) ; /* return p */
35 if (nargout > 6)
36 {
37 pargout [6] = cs_dl_mex_put_int (S->q, n, 1, 0) ; /* return q */
38 }
39 cs_dl_sfree (S) ;
40 }
41