Category : C Source Code
Archive   : RECIPEX.ZIP
Filename : XADI.C

 
Output of file : XADI.C contained in archive : RECIPEX.ZIP
/* Driver for routine ADI */

#include
#include
#include "nr.h"
#include "nrutil.h"

#define JMAX 11
#define PI 3.1415926

main()
{
int i,j,k,mid,twotok;
double alim,alpha,beta,eps;
double **a,**b,**c,**d,**e,**f,**g,**u;

a=dmatrix(1,JMAX,1,JMAX);
b=dmatrix(1,JMAX,1,JMAX);
c=dmatrix(1,JMAX,1,JMAX);
d=dmatrix(1,JMAX,1,JMAX);
e=dmatrix(1,JMAX,1,JMAX);
f=dmatrix(1,JMAX,1,JMAX);
g=dmatrix(1,JMAX,1,JMAX);
u=dmatrix(1,JMAX,1,JMAX);
for (i=1;i<=JMAX;i++) {
for (j=1;j<=JMAX;j++) {
a[i][j] = -1.0;
b[i][j]=2.0;
c[i][j] = -1.0;
d[i][j] = -1.0;
e[i][j]=2.0;
f[i][j] = -1.0;
g[i][j]=0.0;
u[i][j]=0.0;
}
}
mid=JMAX/2+1;
g[mid][mid]=2.0;
alpha=2.0*(1.0-cos(PI/JMAX));
beta=2.0*(1.0-cos((JMAX-1)*PI/JMAX));
alim=log(4.0*JMAX/PI);
k=0;
twotok=1;
while (twotok < alim) {
++k;
twotok *= 2;
}
eps=1.0e-4;
adi(a,b,c,d,e,f,g,u,JMAX,k,alpha,beta,eps);
printf("ADI Solution:\n");
for (i=1;i<=JMAX;i++) {
for (j=1;j<=JMAX;j++) printf("%7.2f",u[i][j]);
printf("\n");
}
printf("\nTest that solution satisfies difference eqns:\n");
for (i=2;i<=JMAX-1;i++) {
for (j=2;j<=JMAX-1;j++)
g[i][j] = -4.0*u[i][j]+u[i+1][j]
+u[i-1][j]+u[i][j-1]+u[i][j+1];
printf(" ");
for (j=2;j<=JMAX-1;j++) printf("%7.2f",g[i][j]);
printf("\n");
}
free_dmatrix(u,1,JMAX,1,JMAX);
free_dmatrix(g,1,JMAX,1,JMAX);
free_dmatrix(f,1,JMAX,1,JMAX);
free_dmatrix(e,1,JMAX,1,JMAX);
free_dmatrix(d,1,JMAX,1,JMAX);
free_dmatrix(c,1,JMAX,1,JMAX);
free_dmatrix(b,1,JMAX,1,JMAX);
free_dmatrix(a,1,JMAX,1,JMAX);
}


  3 Responses to “Category : C Source Code
Archive   : RECIPEX.ZIP
Filename : XADI.C

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

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