#include <stdio.h>
#include <math.h>
#define NRANSI
//#include "nrutil.h"
#include "bibl.h"

#define PI 3.1415926
#define e 0.001

int main(void)
{
int n,ng,i;
double dy,x,y,*xa,*ya,id, *y2,l;
FILE *fp;
fp=fopen("polin21.txt","w");
printf("generation of interpolation tables\n");
printf(" ... 1/(1 + 25*x^2)      -1<x<1\n");
// printf(" ... exp(x)    0<x<1 \n");
printf("Globalnay interpolyciy stepeni 20\n");
n=21;
xa=vector(1,n);
ya=vector(1,n);

for (i=1;i<=n;i++)
    {
        xa[i]=-1.+2.*(i-1.)/(n-1.);
        ya[i]=1./(1.+ 25.*xa[i]*xa[i]);
    }
printf("\n%9s %16s %13s\n","x","interpolated","error");
for (id=-1;id<=1;id+=e)
    {   
        x=id;   
        polint(xa,ya,n,x,&y,&dy);
        printf("%12.6f %12.6f %4s %11f\n",x,y," ",dy);
        fprintf(fp,"%12.6f %12.6f\n",x,y);
    }
free_vector(ya,1,n);
free_vector(xa,1,n);
fclose(fp);

fp=fopen("polin5-21.txt","w");
printf("generation of interpolation tables\n");
printf(" ... 1/(1 + 25*x^2)      -1<x<1\n");
// printf(" ... exp(x)    0<x<1 \n");
printf("Globalnay interpolyciy stepeni 5 po 21 tocke \n");
n=6;
ng=20;
l=-1;
xa=vector(1,n);
ya=vector(1,n);
printf("\n%9s %16s %13s\n","x","interpolated","error");
for(l=-1;l<=1-2.*(n-1.)/(ng);l+=2./ng)
{
    for (i=1;i<=n;i++)
    {
        xa[i]=l+2.*(i-1.)/(ng);
        ya[i]=1./(1.+ 25.*xa[i]*xa[i]);
    }
   
    for (id=l+2*(n/2.-1)/ng;id<l+2*(n/2.)/ng ;id+=e)
    {   
        x=id;   
        polint(xa,ya,n,x,&y,&dy);
        printf("%12.6f %12.6f %4s %11f\n",x,y," ",dy);
        fprintf(fp,"%12.6f %12.6f\n",x,y);
    }
}
free_vector(ya,1,n);
free_vector(xa,1,n);
fclose(fp);

fp=fopen("polin6.txt","w");
printf("generation of interpolation tables\n");
printf(" ... 1/(1 + 25*x^2)      -1<x<1\n");
// printf(" ... exp(x)    0<x<1 \n");
printf("Globalnay interpolyciy stepeni 5\n");
n=6;
xa=vector(1,n);
ya=vector(1,n);

for (i=1;i<=n;i++)
    {
        xa[i]=-1.+2.*(i-1.)/(n-1.);
        ya[i]=1./(1.+ 25.*xa[i]*xa[i]);
    }
printf("\n%9s %16s %13s\n","x","interpolated","error");
for (id=-1;id<=1;id+=e)
    {   
        x=id;   
        polint(xa,ya,n,x,&y,&dy);
        printf("%12.6f %12.6f %4s %11f\n",x,y," ",dy);
        fprintf(fp,"%12.6f %12.6f\n",x,y);
    }
free_vector(ya,1,n);
free_vector(xa,1,n);
fclose(fp);

fp=fopen("spline21.txt","w");
printf("generation of interpolation tables\n");
printf(" ... 1/(1 + 25*x^2)      -1<x<1\n");
// printf(" ... exp(x)    0<x<1 \n");
printf("Sline interpolyciy v 21 tocke\n");   
n=21;
xa=vector(1,n);
ya=vector(1,n);
y2=vector(1,n);
for (i=1;i<=n;i++)
    {
        xa[i]=-1.+2.*(i-1.)/(n-1.);
        ya[i]=1./(1.+ 25.*xa[i]*xa[i]);
    }

    spline(xa,ya,n,0,0,y2);

    printf("\n%9s %17s\n","x","interpolation");
    for (id=-1;id<=1;id+=e)
    {   
    x=id;
    splint(xa,ya,y2,n,x,&y);
    printf("%12.6f %12.6f\n",x,y);
    fprintf(fp,"%12.6f %12.6f\n",x,y);
    }

free_vector(y2,1,n);
free_vector(ya,1,n);
free_vector(xa,1,n);
fclose(fp);
return 0;

}
#undef NRANSI
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