add numerical recipes library

lib/nr/cpp/recipes/red.cpp

@@ -0,0 +1,22 @@
+#include "nr.h"
+
+void NR::red(const int iz1, const int iz2, const int jz1, const int jz2,
+	const int jm1, const int jm2, const int jmf, const int ic1,
+	const int jc1, const int jcf, const int kc, Mat3D_I_DP &c,
+	Mat_IO_DP &s)
+{
+	int loff,l,j,ic,i;
+	DP vx;
+
+	loff=jc1-jm1;
+	ic=ic1;
+	for (j=jz1;j<jz2;j++) {
+		for (l=jm1;l<jm2;l++) {
+			vx=c[ic][l+loff][kc-1];
+			for (i=iz1;i<iz2;i++) s[i][l] -= s[i][j]*vx;
+		}
+		vx=c[ic][jcf][kc-1];
+		for (i=iz1;i<iz2;i++) s[i][jmf] -= s[i][j]*vx;
+		ic += 1;
+	}
+}