			#include <math.h>
			#include "lt.h"

			void polint(double xa,double ya,int n,double x,double y,double dy)
			{
			int i,m,ns=1;
			double den,dif,dift,ho,hp,w;
			double c,d;

			dif=fabs(x-xa[1]);
			c=vector(1,n);
			d=vector(1,n);
			for (i=1;i<=n;i++) {
			if ( (dift=fabs(x-xa[i])) < dif) {
			ns=i;
			dif=dift;
			}
			c[i]=ya[i];
			d[i]=ya[i];
			}
			*y=ya[ns--];
			for (m=1;m<n;m++) {
			for (i=1;i<=n-m;i++) {
			ho=xa[i]-x;
			hp=xa[i+m]-x;
			w=c[i+1]-d[i];
			// Change the error limit from == 0.0 to < 1e-10 EJ030806
			if ( (den=ho-hp) == 0 ) nrerror("Error in routine POLINT");
			den=w/den;
			d[i]=hp*den;
			c[i]=ho*den;
			}
			y += (dy=(2*ns < (n-m) ? c[ns+1] : d[ns--]));
			}
			free_vector(d,1);
			free_vector(c,1);
			}

R1448/ChiBenchmark/lenstoolchi/liblt/polint.c
c99f2e455a51gridgradient

polint.c
View Options