add numerical recipes library

lib/nr/cpp/recipes/predic.cpp

@@ -0,0 +1,20 @@
+#include "nr.h"
+
+void NR::predic(Vec_I_DP &data, Vec_I_DP &d, Vec_O_DP &future)
+{
+	int k,j;
+	DP sum,discrp;
+
+	int ndata=data.size();
+	int m=d.size();
+	int nfut=future.size();
+	Vec_DP reg(m);
+	for (j=0;j<m;j++) reg[j]=data[ndata-1-j];
+	for (j=0;j<nfut;j++) {
+		discrp=0.0;
+		sum=discrp;
+		for (k=0;k<m;k++) sum += d[k]*reg[k];
+		for (k=m-1;k>=1;k--) reg[k]=reg[k-1];
+		future[j]=reg[0]=sum;
+	}
+}