int sparse_solve_cholesky(sparse_matrix* matrix, sparse_vector* b, sparse_vector* x, int n){
if( n < 1)
return 0;
memcpy(x,b,n*sizeof(double));
return cs_cholsol(1 , matrix , x);
}
/* solve a linear system using Cholesky, LU, and QR, with various orderings */
int demo2 (problem *Prob)
{
cs *A, *C ;
double *b, *x, *resid, t, tol ;
int k, m, n, ok, order, nb, ns, *r, *s, *rr, sprank ;
csd *D ;
if (!Prob) return (0) ;
A = Prob->A ; C = Prob->C ; b = Prob->b ; x = Prob->x ; resid = Prob->resid;
m = A->m ; n = A->n ;
tol = Prob->sym ? 0.001 : 1 ; /* partial pivoting tolerance */
D = cs_dmperm (C, 1) ; /* randomized dmperm analysis */
if (!D) return (0) ;
nb = D->nb ; r = D->r ; s = D->s ; rr = D->rr ;
sprank = rr [3] ;
for (ns = 0, k = 0 ; k < nb ; k++)
{
ns += ((r [k+1] == r [k]+1) && (s [k+1] == s [k]+1)) ;
}
printf ("blocks: %g singletons: %g structural rank: %g\n",
(double) nb, (double) ns, (double) sprank) ;
cs_dfree (D) ;
for (order = 0 ; order <= 3 ; order += 3) /* natural and amd(A'*A) */
{
if (!order && m > 1000) continue ;
printf ("QR ") ;
print_order (order) ;
rhs (x, b, m) ; /* compute right-hand side */
t = tic () ;
ok = cs_qrsol (order, C, x) ; /* min norm(Ax-b) with QR */
printf ("time: %8.2f ", toc (t)) ;
print_resid (ok, C, x, b, resid) ; /* print residual */
}
if (m != n || sprank < n) return (1) ; /* return if rect. or singular*/
for (order = 0 ; order <= 3 ; order++) /* try all orderings */
{
if (!order && m > 1000) continue ;
printf ("LU ") ;
print_order (order) ;
rhs (x, b, m) ; /* compute right-hand side */
t = tic () ;
ok = cs_lusol (order, C, x, tol) ; /* solve Ax=b with LU */
printf ("time: %8.2f ", toc (t)) ;
print_resid (ok, C, x, b, resid) ; /* print residual */
}
if (!Prob->sym) return (1) ;
for (order = 0 ; order <= 1 ; order++) /* natural and amd(A+A') */
{
if (!order && m > 1000) continue ;
printf ("Chol ") ;
print_order (order) ;
rhs (x, b, m) ; /* compute right-hand side */
t = tic () ;
ok = cs_cholsol (order, C, x) ; /* solve Ax=b with Cholesky */
printf ("time: %8.2f ", toc (t)) ;
print_resid (ok, C, x, b, resid) ; /* print residual */
}
return (1) ;
}
bool solve_sparse(int* px,int *py,double *pv,double *pB,int sz,int N) {
cs a;
a.m = a.n = N;
a.nz = a.nzmax = sz;
a.p = px; a.i = py;
a.x = pv;
cs *pa = cs_compress(&a);
int nRet = cs_cholsol(1,pa,pB);
cs_spfree(pa);
return 0 != nRet;
}
