add numerical recipes library

lib/nr/ansi/examples/xhypgeo.c

@@ -0,0 +1,44 @@
+
+/* Driver for routine hypgeo */
+
+#include <stdio.h>
+#include <math.h>
+#define NRANSI
+#include "nr.h"
+#include "nrutil.h"
+#include "complex.h"
+
+fcomplex Clog(fcomplex a)
+{
+	fcomplex b;
+
+	b.r=log(Cabs(a));
+	b.i=atan2(a.i,a.r);
+	return b;
+}
+
+int main(void)
+{
+	fcomplex a,b,c,z,zi,q1,q2,q3,q4;
+	float x,y;
+
+	a=Complex(0.5,0.0);
+	b=Complex(1.0,0.0);
+	c=Complex(1.5,0.0);
+	for (;;) {
+		printf("INPUT X,Y OF COMPLEX ARGUMENT:\n");
+		if (scanf("%f %f",&x,&y) == EOF) break;
+		z=Complex(x,y);
+		q1=hypgeo(a,b,c,Cmul(z,z));
+		q2=RCmul(0.5,Cdiv(Clog(Cdiv(Cadd(b,z),Csub(b,z))),z));
+		q3=hypgeo(a,b,c,RCmul(-1.0,Cmul(z,z)));
+		zi=Complex(-y,x);
+		q4=RCmul(0.5,Cdiv(Clog(Cdiv(Cadd(b,zi),Csub(b,zi))),zi));
+		printf("2F1(0.5,1.0,1.5;z^2) =%12.6f %12.6f\n",q1.r,q1.i);
+		printf("check using log form: %12.6f %12.6f\n",q2.r,q2.i);
+		printf("2F1(0.5,1.0,1.5;-z^2)=%12.6f %12.6f\n",q3.r,q3.i);
+		printf("check using log form: %12.6f %12.6f\n",q4.r,q4.i);
+	}
+	return 0;
+}
+#undef NRANSI