Esempio n. 1
0
/* read a problem from a file; use %g for integers to avoid cs_long_t conflicts */
problem *get_problem (FILE *f, double tol)
{
    cs_cl *T, *A, *C ;
    cs_long_t sym, m, n, mn, nz1, nz2 ;
    problem *Prob ;
    Prob = cs_cl_calloc (1, sizeof (problem)) ;
    if (!Prob) return (NULL) ;
    T = cs_cl_load (f) ;                   /* load triplet matrix T from a file */
    Prob->A = A = cs_cl_compress (T) ;     /* A = compressed-column form of T */
    cs_cl_spfree (T) ;                     /* clear T */
    if (!cs_cl_dupl (A)) return (free_problem (Prob)) ; /* sum up duplicates */
    Prob->sym = sym = is_sym (A) ;      /* determine if A is symmetric */
    m = A->m ; n = A->n ;
    mn = CS_MAX (m,n) ;
    nz1 = A->p [n] ;
    cs_cl_dropzeros (A) ;                  /* drop zero entries */
    nz2 = A->p [n] ;
    if (tol > 0) cs_cl_droptol (A, tol) ;  /* drop tiny entries (just to test) */
    Prob->C = C = sym ? make_sym (A) : A ;  /* C = A + triu(A,1)', or C=A */
    if (!C) return (free_problem (Prob)) ;
    printf ("\n--- Matrix: %g-by-%g, nnz: %g (sym: %g: nnz %g), norm: %8.2e\n",
            (double) m, (double) n, (double) (A->p [n]), (double) sym,
            (double) (sym ? C->p [n] : 0), cs_cl_norm (C)) ;
    if (nz1 != nz2) printf ("zero entries dropped: %g\n", (double) (nz1 - nz2));
    if (nz2 != A->p [n]) printf ("tiny entries dropped: %g\n",
            (double) (nz2 - A->p [n])) ;
    Prob->b = cs_cl_malloc (mn, sizeof (cs_complex_t)) ;
    Prob->x = cs_cl_malloc (mn, sizeof (cs_complex_t)) ;
    Prob->resid = cs_cl_malloc (mn, sizeof (cs_complex_t)) ;
    return ((!Prob->b || !Prob->x || !Prob->resid) ? free_problem (Prob) : Prob) ;
}
Esempio n. 2
0
/* cs_sparse: convert triplet form into compress-column form sparse matrix */
void mexFunction
(
    int nargout,
    mxArray *pargout [ ],
    int nargin,
    const mxArray *pargin [ ]
)
{
    if (nargout > 1 || nargin != 3)
    {
        mexErrMsgTxt ("Usage: A = cs_sparse(i,j,x)") ;
    }
    if (mxIsComplex (pargin [2]))
    {
#ifndef NCOMPLEX
        cs_cl *A, *C, *T, Tmatrix ;
        T = &Tmatrix ;                  /* get i,j,x and copy to triplet form */
        T->nz = mxGetM (pargin [0]) ;
        T->p = cs_dl_mex_get_int (T->nz, pargin [0], &(T->n), 1) ;
        T->i = cs_dl_mex_get_int (T->nz, pargin [1], &(T->m), 1) ;
        cs_mex_check (1, T->nz, 1, 0, 0, 1, pargin [2]) ;
        T->x = cs_cl_mex_get_double (T->nz, pargin [2]) ;
        T->nzmax = T->nz ;
        C = cs_cl_compress (T) ;                /* create sparse matrix C */
        cs_cl_dupl (C) ;                        /* remove duplicates from C */
        cs_cl_dropzeros (C) ;                   /* remove zeros from C */
        A = cs_cl_transpose (C, -1) ;           /* A=C.' */
        cs_cl_spfree (C) ;
        pargout [0] = cs_cl_mex_put_sparse (&A) ;       /* return A */
        cs_free (T->p) ;
        cs_free (T->i) ;
        cs_free (T->x) ;                        /* free copy of complex values*/
#else
        mexErrMsgTxt ("complex matrices not supported") ;
#endif
    }
    else
    {
        cs_dl *A, *C, *T, Tmatrix ;
        T = &Tmatrix ;                  /* get i,j,x and copy to triplet form */
        T->nz = mxGetM (pargin [0]) ;
        T->p = cs_dl_mex_get_int (T->nz, pargin [0], &(T->n), 1) ;
        T->i = cs_dl_mex_get_int (T->nz, pargin [1], &(T->m), 1) ;
        cs_mex_check (1, T->nz, 1, 0, 0, 1, pargin [2]) ;
        T->x = mxGetPr (pargin [2]) ;
        T->nzmax = T->nz ;
        C = cs_dl_compress (T) ;                /* create sparse matrix C */
        cs_dl_dupl (C) ;                        /* remove duplicates from C */
        cs_dl_dropzeros (C) ;                   /* remove zeros from C */
        A = cs_dl_transpose (C, 1) ;            /* A=C' */
        cs_dl_spfree (C) ;
        pargout [0] = cs_dl_mex_put_sparse (&A) ;       /* return A */
        cs_free (T->p) ;
        cs_free (T->i) ;
    }
}