add numerical recipes library

lib/nr/ansi/examples/xpredic.c

@@ -0,0 +1,42 @@
+
+/* Driver for routine predic */
+
+#include <stdio.h>
+#include <math.h>
+#define NRANSI
+#include "nr.h"
+#include "nrutil.h"
+
+#define NPTS 500
+#define NPOLES 10
+#define NFUT 20
+#define PI 3.1415926
+
+float f(int n,int npts)
+{
+	return exp(-(1.0*n)/npts)*sin(2.0*PI*n/50.0)
+		+exp(-(2.0*n)/npts)*sin(2.2*PI*n/50.0);
+}
+
+int main(void)
+{
+	int i;
+	float dum,*d,*future,*data;
+
+	d=vector(1,NPOLES);
+	future=vector(1,NFUT);
+	data=vector(1,NPTS);
+	for (i=1;i<=NPTS;i++)
+		data[i]=f(i,NPTS);
+	memcof(data,NPTS,NPOLES,&dum,d);
+	fixrts(d,NPOLES);
+	predic(data,NPTS,d,NPOLES,future,NFUT);
+	printf("%6s %11s %12s\n","I","Actual","PREDIC");
+	for (i=1;i<=NFUT;i++)
+		printf("%6d %12.6f %12.6f\n",i,f(i+NPTS,NPTS),future[i]);
+	free_vector(data,1,NPTS);
+	free_vector(future,1,NFUT);
+	free_vector(d,1,NPOLES);
+	return 0;
+}
+#undef NRANSI