add numerical recipes library

lib/nr/ansi/examples/xbcuint.c

@@ -0,0 +1,42 @@
+
+/* Driver for routine bcuint */
+
+#include <stdio.h>
+#define NRANSI
+#include "nr.h"
+
+int main(void)
+{
+	int i;
+	float ansy,ansy1,ansy2,ey,ey1,ey2;
+	float x1,x1l,x1u,x1x2,x2,x2l,x2u,xxyy;
+	float y[5],y1[5],y12[5],y2[5];
+	static float xx[]={0.0,0.0,2.0,2.0,0.0};
+	static float yy[]={0.0,0.0,0.0,2.0,2.0};
+
+	x1l=xx[1];
+	x1u=xx[2];
+	x2l=yy[1];
+	x2u=yy[4];
+	for (i=1;i<=4;i++) {
+		xxyy=xx[i]*yy[i];
+		y[i]=xxyy*xxyy;
+		y1[i]=2.0*yy[i]*xxyy;
+		y2[i]=2.0*xx[i]*xxyy;
+		y12[i]=4.0*xxyy;
+	}
+	printf("\n%6s %8s %7s %11s %6s %10s %6s %10s \n\n",
+		"x1","x2","y","expect","y1","expect","y2","expect");
+	for (i=1;i<=10;i++) {
+		x2=(x1=0.2*i);
+		bcuint(y,y1,y2,y12,x1l,x1u,x2l,x2u,x1,x2,&ansy,&ansy1,&ansy2);
+		x1x2=x1*x2;
+		ey=x1x2*x1x2;
+		ey1=2.0*x2*x1x2;
+		ey2=2.0*x1*x1x2;
+		printf("%8.4f %8.4f %8.4f %8.4f %8.4f %8.4f %8.4f %8.4f\n",
+			x1,x2,ansy,ey,ansy1,ey1,ansy2,ey2);
+	}
+	return 0;
+}
+#undef NRANSI