add numerical recipes library

lib/nr/ansi/recipes/banmul.c

@@ -0,0 +1,16 @@
+
+#define NRANSI
+#include "nrutil.h"
+
+void banmul(float **a, unsigned long n, int m1, int m2, float x[], float b[])
+{
+	unsigned long i,j,k,tmploop;
+
+	for (i=1;i<=n;i++) {
+		k=i-m1-1;
+		tmploop=LMIN(m1+m2+1,n-k);
+		b[i]=0.0;
+		for (j=LMAX(1,1-k);j<=tmploop;j++) b[i] += a[i][j]*x[j+k];
+	}
+}
+#undef NRANSI