void atimes(unsigned long n, double x[], double r[], int itrnsp)
{
void dsprsax(double sa[], unsigned long ija[], double x[], double b[],
unsigned long n);
void dsprstx(double sa[], unsigned long ija[], double x[], double b[],
unsigned long n);
if (itrnsp) dsprstx(sa,ija,x,r,n);
else dsprsax(sa,ija,x,r,n);
}
int main(void)
{
int i,ii,iter;
double *b,*bcmp,*x,err;
b=dvector(1,NP);
bcmp=dvector(1,NP);
x=dvector(1,NP);
for (i=1;i<=NP;i++) {
x[i]=0.0;
b[i]=1.0;
}
b[1]=3.0;
b[NP] = -1.0;
linbcg(NP,b,x,ITOL,TOL,ITMAX,&iter,&err);
printf("%s %15e\n","Estimated error:",err);
printf("%s %6d\n","Iterations needed:",iter);
printf("\nSolution vector:\n");
for (ii=1;ii<=NP/5;ii++) {
for (i=5*(ii-1)+1;i<=5*ii;i++) printf("%12.6f",x[i]);
printf("\n");
}
for (i=1;i<=(NP % 5);i++)
printf("%12.6f",x[5*(NP/5)+i]);
printf("\n");
dsprsax(sa,ija,x,bcmp,NP);
/* this is a double precision version of sprsax */
printf("\npress RETURN to continue...\n");
(void) getchar();
printf("test of solution vector:\n");
printf("%9s %12s\n","a*x","b");
for (i=1;i<=NP;i++)
printf("%12.6f %12.6f\n",bcmp[i],b[i]);
free_dvector(x,1,NP);
free_dvector(bcmp,1,NP);
free_dvector(b,1,NP);
return 0;
}
void PCBCGSolver::atimes(unsigned long n, double x[], double r[], int itrnsp) {
if (itrnsp) dsprstx(sa,ija,x,r,n);
else dsprsax(sa,ija,x,r,n);
}
