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add numerical recipes library

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yenru0
2025-09-12 18:55:25 +09:00
parent d4dff245bd
commit 2c75620ec9
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59
lib/nr/ansi/examples/xsor.c Normal file
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/* Driver for routine sor */
#include <stdio.h>
#include <math.h>
#define NRANSI
#include "nr.h"
#include "nrutil.h"
#define NSTEP 4
#define JMAX 33
#define PI 3.1415926
int main(void)
{
int i,j,midl;
double **a,**b,**c,**d,**e,**f,**u,rjac;
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);
u=dmatrix(1,JMAX,1,JMAX);
for (i=1;i<=JMAX;i++)
for (j=1;j<=JMAX;j++) {
a[i][j]=b[i][j]=c[i][j]=d[i][j]=1.0;
e[i][j]=(-4.0);
f[i][j]=u[i][j]=0.0;
}
midl=JMAX/2+1;
f[midl][midl]=2.0/((JMAX-1)*(JMAX-1));
rjac=cos(PI/JMAX);
sor(a,b,c,d,e,f,u,JMAX,rjac);
printf("SOR solution:\n");
for (i=1;i<=JMAX;i+=NSTEP) {
for (j=1;j<=JMAX;j+=NSTEP) printf("%8.4f",u[i][j]);
printf("\n");
}
printf("\n Test that solution satisfies difference equations:\n");
for (i=NSTEP+1;i<JMAX;i+=NSTEP) {
for (j=NSTEP+1;j<JMAX;j+=NSTEP)
f[i][j]=u[i+1][j]+u[i-1][j]+u[i][j+1]+u[i][j-1]
-4.0*u[i][j];
printf("%7s"," ");
for (j=NSTEP+1;j<JMAX;j+=NSTEP) printf("%8.4f",f[i][j]);
printf("\n");
}
free_dmatrix(u,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);
return 0;
}
#undef NRANSI