add numerical recipes library

lib/nr/ansi/examples/xrzextr.c

@@ -0,0 +1,52 @@
+
+/* Driver for routine rzextr */
+
+#include <stdio.h>
+#define NRANSI
+#include "nr.h"
+#include "nrutil.h"
+
+#define NV 4
+#define IMAXX 10
+
+float **d,*x;   /* defining declaration */
+
+int main(void)
+{
+	int i,iest,j;
+	float dum,xest,*dy,*yest,*yz;
+
+	dy=vector(1,NV);
+	yest=vector(1,NV);
+	yz=vector(1,NV);
+	x=vector(1,IMAXX);
+	d=matrix(1,IMAXX,1,IMAXX);
+	/* Feed values from a rational function */
+	/* fn(x)=(1-x+x**3)/(x+1)**n */
+	for (i=1;i<=IMAXX;i++) {
+		iest=i;
+		xest=1.0/i;
+		dum=1.0-xest+xest*xest*xest;
+		for (j=1;j<=NV;j++) {
+			dum /= (xest+1.0);
+			yest[j]=dum;
+		}
+		rzextr(iest,xest,yest,yz,dy,NV);
+		printf("\n%s %2d %s %8.4f\n",
+			"iest = ",i,"    xest =",xest);
+		printf("Extrap. function: ");
+		for (j=1;j<=NV;j++) printf("%12.6f",yz[j]);
+		printf("\nEstimated error:  ");
+		for (j=1;j<=NV;j++) printf("%12.6f",dy[j]);
+		printf("\n");
+	}
+	printf("\nActual values: %15.6f %11.6f %11.6f %11.6f \n",
+		1.0,1.0,1.0,1.0);
+	free_matrix(d,1,IMAXX,1,IMAXX);
+	free_vector(x,1,IMAXX);
+	free_vector(yz,1,NV);
+	free_vector(yest,1,NV);
+	free_vector(dy,1,NV);
+	return 0;
+}
+#undef NRANSI