add numerical recipes library

lib/nr/k_and_r/recipes/banmul.c

@@ -0,0 +1,17 @@
+
+#include "nrutil.h"
+
+void banmul(a,n,m1,m2,x,b)
+float **a,b[],x[];
+int m1,m2;
+unsigned long n;
+{
+	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];
+	}
+}