add numerical recipes library

lib/nr/cpp/recipes/amotsa.cpp

@@ -0,0 +1,35 @@
+#include <cmath>
+#include "nr.h"
+using namespace std;
+
+extern int idum;
+extern DP tt;
+
+DP NR::amotsa(Mat_IO_DP &p, Vec_O_DP &y, Vec_IO_DP &psum, Vec_O_DP &pb, DP &yb,
+	DP funk(Vec_I_DP &), const int ihi, DP &yhi, const DP fac)
+{
+	int j;
+	DP fac1,fac2,yflu,ytry;
+
+	int ndim=p.ncols();
+	Vec_DP ptry(ndim);
+	fac1=(1.0-fac)/ndim;
+	fac2=fac1-fac;
+	for (j=0;j<ndim;j++)
+		ptry[j]=psum[j]*fac1-p[ihi][j]*fac2;
+	ytry=funk(ptry);
+	if (ytry <= yb) {
+		for (j=0;j<ndim;j++) pb[j]=ptry[j];
+		yb=ytry;
+	}
+	yflu=ytry-tt*log(ran1(idum));
+	if (yflu < yhi) {
+		y[ihi]=ytry;
+		yhi=yflu;
+		for (j=0;j<ndim;j++) {
+			psum[j] += ptry[j]-p[ihi][j];
+			p[ihi][j]=ptry[j];
+		}
+	}
+	return yflu;
+}