add numerical recipes library

lib/nr/cpp/recipes/poldiv.cpp

@@ -0,0 +1,18 @@
+#include "nr.h"
+
+void NR::poldiv(Vec_I_DP &u, Vec_I_DP &v, Vec_O_DP &q, Vec_O_DP &r)
+{
+	int k,j;
+
+	int n=u.size()-1;
+	int nv=v.size()-1;
+	for (j=0;j<=n;j++) {
+		r[j]=u[j];
+		q[j]=0.0;
+	}
+	for (k=n-nv;k>=0;k--) {
+		q[k]=r[nv+k]/v[nv];
+		for (j=nv+k-1;j>=k;j--) r[j] -= q[k]*v[j-k];
+	}
+	for (j=nv;j<=n;j++) r[j]=0.0;
+}