add numerical recipes library

lib/nr/ansi/recipes/simp3.c

@@ -0,0 +1,18 @@
+
+void simp3(float **a, int i1, int k1, int ip, int kp)
+{
+	int kk,ii;
+	float piv;
+
+	piv=1.0/a[ip+1][kp+1];
+	for (ii=1;ii<=i1+1;ii++)
+		if (ii-1 != ip) {
+			a[ii][kp+1] *= piv;
+			for (kk=1;kk<=k1+1;kk++)
+				if (kk-1 != kp)
+					a[ii][kk] -= a[ip+1][kk]*a[ii][kp+1];
+		}
+	for (kk=1;kk<=k1+1;kk++)
+		if (kk-1 != kp) a[ip+1][kk] *= -piv;
+	a[ip+1][kp+1]=piv;
+}