add numerical recipes library

lib/nr/ansi/recipes/mprove.c

@@ -0,0 +1,22 @@
+
+#define NRANSI
+#include "nrutil.h"
+
+void mprove(float **a, float **alud, int n, int indx[], float b[], float x[])
+{
+	void lubksb(float **a, int n, int *indx, float b[]);
+	int j,i;
+	double sdp;
+	float *r;
+
+	r=vector(1,n);
+	for (i=1;i<=n;i++) {
+		sdp = -b[i];
+		for (j=1;j<=n;j++) sdp += a[i][j]*x[j];
+		r[i]=sdp;
+	}
+	lubksb(alud,n,indx,r);
+	for (i=1;i<=n;i++) x[i] -= r[i];
+	free_vector(r,1,n);
+}
+#undef NRANSI