add numerical recipes library

lib/nr/ansi/examples/xbcucof.c

@@ -0,0 +1,38 @@
+
+/* Driver for routine bcucof */
+
+#include <stdio.h>
+#include <math.h>
+#define NRANSI
+#include "nr.h"
+#include "nrutil.h"
+
+int main(void)
+{
+	int i,j;
+	float d1,d2,ee,x1x2;
+	float y[5],y1[5],y2[5],y12[5],**c;
+	static float x1[]={0.0,0.0,2.0,2.0,0.0};
+	static float x2[]={0.0,0.0,0.0,2.0,2.0};
+
+	c=matrix(1,4,1,4);
+	d1=x1[2]-x1[1];
+	d2=x2[4]-x2[1];
+	for (i=1;i<=4;i++) {
+		x1x2=x1[i]*x2[i];
+		ee=exp(-x1x2);
+		y[i]=x1x2*ee;
+		y1[i]=x2[i]*(1.0-x1x2)*ee;
+		y2[i]=x1[i]*(1.0-x1x2)*ee;
+		y12[i]=(1.0-3.0*x1x2+x1x2*x1x2)*ee;
+	}
+	bcucof(y,y1,y2,y12,d1,d2,c);
+	printf("\nCoefficients for bicubic interpolation:\n\n");
+	for (i=1;i<=4;i++) {
+		for (j=1;j<=4;j++) printf("%12.6f",c[i][j]);
+		printf("\n");
+	}
+	free_matrix(c,1,4,1,4);
+	return 0;
+}
+#undef NRANSI