add numerical recipes library

lib/nr/cpp/recipes/quadmx.cpp

@@ -0,0 +1,24 @@
+#include <cmath>
+#include "nr.h"
+using namespace std;
+
+DP x;
+
+void NR::quadmx(Mat_O_DP &a)
+{
+	const DP PI=3.14159263589793238;
+	int j,k;
+	DP h,xx,cx;
+
+	int n=a.nrows();
+	Vec_DP wt(n);
+	h=PI/(n-1);
+	for (j=0;j<n;j++) {
+		x=xx=j*h;
+		wwghts(wt,h,kermom);
+		cx=cos(xx);
+		for (k=0;k<n;k++)
+			a[j][k]=wt[k]*cx*cos(k*h);
+		++a[j][j];
+	}
+}