#include <math.h>#define NRANSI#include "nrutil.h"#define TINY 1.0e-25#define FREERETURN {free_vector(d,1,n);free_vector(c,1,n);return;}void ratint(float xa[], float ya[], int n, float x, float *y, float *dy){	int m,i,ns=1;	float w,t,hh,h,dd,*c,*d;	c=vector(1,n);	d=vector(1,n);	hh=fabs(x-xa[1]);	for (i=1;i<=n;i++) {		h=fabs(x-xa[i]);		if (h == 0.0) {			*y=ya[i];			*dy=0.0;			FREERETURN		} else if (h < hh) {			ns=i;			hh=h;		}		c[i]=ya[i];		d[i]=ya[i]+TINY;	}	*y=ya[ns--];	for (m=1;m<n;m++) {		for (i=1;i<=n-m;i++) {			w=c[i+1]-d[i];			h=xa[i+m]-x;			t=(xa[i]-x)*d[i]/h;			dd=t-c[i+1];			if (dd == 0.0) nrerror("Error in routine ratint");			dd=w/dd;			d[i]=c[i+1]*dd;			c[i]=t*dd;		}		*y += (*dy=(2*ns < (n-m) ? c[ns+1] : d[ns--]));	}	FREERETURN}#undef TINY#undef FREERETURN#undef NRANSI