add numerical recipes library

2025-09-12 18:55:25 +09:00
parent d4dff245bd
commit 2c75620ec9
1344 changed files with 63869 additions and 0 deletions
--- a/lib/nr/cpp/recipes/hypgeo.cpp
+++ b/lib/nr/cpp/recipes/hypgeo.cpp
@@ -0,0 +1,41 @@
+#include <cmath>
+#include <complex>
+#include "nr.h"
+using namespace std;
+
+complex<DP> aa,bb,cc,z0,dz;
+
+int kmax,kount;
+DP dxsav;
+Vec_DP *xp_p;
+Mat_DP *yp_p;
+
+complex<DP> NR::hypgeo(const complex<DP> &a, const complex<DP> &b,
+	const complex<DP> &c, const complex<DP> &z)
+{
+	const DP EPS=1.0e-14;
+	int nbad,nok;
+	complex<DP> ans,y[2];
+	Vec_DP yy(4);
+
+	kmax=0;
+	if (norm(z) <= 0.25) {
+		hypser(a,b,c,z,ans,y[1]);
+		return ans;
+	}
+	else if (real(z) < 0.0) z0=complex<DP>(-0.5,0.0);
+	else if (real(z) <= 1.0) z0=complex<DP>(0.5,0.0);
+	else z0=complex<DP>(0.0,imag(z) >= 0.0 ? 0.5 : -0.5);
+	aa=a;
+	bb=b;
+	cc=c;
+	dz=z-z0;
+	hypser(aa,bb,cc,z0,y[0],y[1]);
+	yy[0]=real(y[0]);
+	yy[1]=imag(y[0]);
+	yy[2]=real(y[1]);
+	yy[3]=imag(y[1]);
+	odeint(yy,0.0,1.0,EPS,0.1,0.0001,nok,nbad,hypdrv,bsstep);
+	y[0]=complex<DP>(yy[0],yy[1]);
+	return y[0];
+}