1 #include "cs_mex.h"
2 /* cs_utsolve: solve a lower triangular system U'*x=b */
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 if (nargout > 1 || nargin != 2)
12 {
13 mexErrMsgTxt ("Usage: x = cs_utsolve(U,b)") ;
14 }
15 if (mxIsComplex (pargin [0]) || mxIsComplex (pargin [1]))
16 {
17 #ifndef NCOMPLEX
18 cs_cl Umatrix, *U ;
19 cs_complex_t *x ;
20 U = cs_cl_mex_get_sparse (&Umatrix, 1, pargin [0]) ; /* get U */
21 x = cs_cl_mex_get_double (U->n, pargin [1]) ; /* x = b */
22 cs_cl_utsolve (U, x) ; /* x = U'\x */
23 cs_free (U->x) ;
24 pargout [0] = cs_cl_mex_put_double (U->n, x) ; /* return x */
25 #else
26 mexErrMsgTxt ("complex matrices not supported") ;
27 #endif
28 }
29 else
30 {
31 cs_dl Umatrix, *U ;
32 double *x, *b ;
33 U = cs_dl_mex_get_sparse (&Umatrix, 1, 1, pargin [0]) ; /* get U */
34 b = cs_dl_mex_get_double (U->n, pargin [1]) ; /* get b */
35 x = cs_dl_mex_put_double (U->n, b, &(pargout [0])) ; /* x = b */
36 cs_dl_utsolve (U, x) ; /* x = U'\x */
37 }
38 }
39