64 lines
1.2 KiB
C
64 lines
1.2 KiB
C
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/* Driver for routine polcoe */
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#include <stdio.h>
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#include <math.h>
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#define NRANSI
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#include "nr.h"
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#include "nrutil.h"
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#define NP 4
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#define PI 3.1415926
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int main(void)
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{
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int i,j,nfunc;
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float f,sum,x,*coeff,*xa,*ya;
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coeff=vector(0,NP);
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xa=vector(0,NP);
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ya=vector(0,NP);
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for (nfunc=1;nfunc<=2;nfunc++) {
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if (nfunc == 1) {
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printf("sine function from 0 to PI\n\n");
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for (i=0;i<=NP;i++) {
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xa[i]=(i+1)*PI/(NP+1);
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ya[i]=sin(xa[i]);
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}
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} else if (nfunc == 2) {
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printf("exponential function from 0 to 1\n\n");
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for (i=0;i<=NP;i++) {
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xa[i]=1.0*(i+1)/(NP+1);
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ya[i]=exp(xa[i]);
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}
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} else {
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break;
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}
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polcoe(xa,ya,NP,coeff);
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printf(" coefficients\n");
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for (i=0;i<=NP;i++) printf("%12.6f",coeff[i]);
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printf("\n\n%9s %13s %15s\n","x","f(x)","polynomial");
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for (i=1;i<=10;i++) {
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if (nfunc == 1) {
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x=(-0.05+i/10.0)*PI;
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f=sin(x);
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} else if (nfunc == 2) {
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x = -0.05+i/10.0;
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f=exp(x);
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}
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sum=coeff[NP];
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for (j=NP-1;j>=0;j--)
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sum=coeff[j]+sum*x;
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printf("%12.6f %12.6f %12.6f\n",x,f,sum);
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}
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printf("\n************************************\n");
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printf("press RETURN\n");
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(void) getchar();
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}
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free_vector(ya,0,NP);
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free_vector(xa,0,NP);
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free_vector(coeff,0,NP);
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return 0;
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}
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#undef NRANSI
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