int estiva_cgsolver(void *A, double *x, double *b)
{
static double *work;
long n, ldw, iter, info, i;
double resid = 1.0e-7;
if ( !symcheckmx(A) ) {
fprintf(stderr,"matrix is not symmetric\n");
return 1;
}
setAmx(A);
ldw = iter = n = dim1(b);
ary1(work,n*4+1);
setveclength(n);
forall (0, i, n ) x[i] = b[i];
ILUdecomp(A);
distributemx(A);
cg_(&n,b+1,x+1,work,&ldw,&iter,&resid,estiva_matvecmpi2,estiva_psolve,&info);
if (defop("-v")) fprintf(stderr, "cg iter = %ld\n",iter);
return 0;
}
int
check_cg_pc (int n,
int it_max, double it_eps,
int verbose, double tiny)
{
if (verbose != 0)
{
fprintf (stdout,
"==================================================\n"
"check_cg_pc(n=%d): start\n", n);
}
int check = 0;
double max = 0.0;
double *a = (double *)malloc (sizeof (double) * n * n);
double *b = (double *)malloc (sizeof (double) * n);
double *x = (double *)malloc (sizeof (double) * n);
double *x_ = (double *)malloc (sizeof (double) * n);
double *lu = (double *)malloc (sizeof (double) * n * n);
CHECK_MALLOC (a, "check_cg_pc");
CHECK_MALLOC (b, "check_cg_pc");
CHECK_MALLOC (x, "check_cg_pc");
CHECK_MALLOC (x_, "check_cg_pc");
CHECK_MALLOC (lu, "check_cg_pc");
// symmetric matrix
int i, j;
for (i = 0; i < n; i ++)
{
a[i * n + i] = (double)(i+1);
for (j = i+1; j < n; j ++)
{
a[i * n + j] = 1.0/(double)(i+j);
a[j * n + i] = 1.0/(double)(i+j);
}
}
srand48(0);
for (i = 0; i < n; i ++)
{
b[i] = drand48();
}
struct iter *it
= iter_init ("cg", it_max, 0, it_eps, // solver param
n, NULL, 0, // guess
0, NULL); // debug info
CHECK_MALLOC (it, "check_cg_pc");
char label[80];
// cg_
for (i = 0; i < n; i ++)
{
x[i] = 0.0;
}
double t0 = ptime_ms_d ();
cg_ (n, b, x,
local_atimes, (void *)a,
it);
double t1 = ptime_ms_d ();
if (verbose != 0)
{
fprintf (stdout, "cg_ "
"iter = %d, res = %e, CPU time = %f\n",
it->niter, sqrt(it->res2), t1 - t0);
}
// cg_pc with inv_diag()
for (i = 0; i < n; i ++)
{
x_[i] = 0.0;
}
t0 = ptime_ms_d ();
cg_pc (n, b, x_,
local_atimes, (void *)a,
inv_diag, (void *)a,
it);
t1 = ptime_ms_d ();
if (verbose != 0)
{
fprintf (stdout, "cg_pc(diag) "
"iter = %d, res = %e, CPU time = %f\n",
it->niter, sqrt(it->res2), t1 - t0);
}
for (i = 0; i < n; i ++)
{
sprintf (label, "x[%d]", i);
check += compare_max (x[i], x_[i], label, verbose, tiny, &max);
}
// cg_pc with inv_ILU()
for (i = 0; i < n; i ++)
{
x_[i] = 0.0;
}
LU_Gauss (n, a, lu);
t0 = ptime_ms_d ();
cg_pc (n, b, x_,
local_atimes, (void *)a,
inv_ILU, (void *)lu,
it);
t1 = ptime_ms_d ();
if (verbose != 0)
{
fprintf (stdout, "cg_pc(LU) "
"iter = %d, res = %e, CPU time = %f\n",
it->niter, sqrt(it->res2), t1 - t0);
}
for (i = 0; i < n; i ++)
{
sprintf (label, "x[%d]", i);
check += compare_max (x[i], x_[i], label, verbose, tiny, &max);
}
iter_free (it);
free (a);
free (b);
free (x);
free (x_);
free (lu);
if (verbose != 0)
{
fprintf (stdout, " max error = %e vs tiny = %e\n", max, tiny);
if (check == 0) fprintf (stdout, " => PASSED\n\n");
else fprintf (stdout, " => FAILED\n\n");
}
return (check);
}
