Category : C Source Code
Archive   : RECIPEX.ZIP
Filename : XADI.C
#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);
}
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This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.
But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/