add numerical recipes library

lib/nr/ansi/examples/xmoment.c

@@ -0,0 +1,42 @@
+
+/* Driver for routine moment */
+
+#include <stdio.h>
+#include <math.h>
+#define NRANSI
+#include "nr.h"
+#include "nrutil.h"
+
+#define PI 3.14159265
+#define NPTS 5000
+#define NBIN 100
+#define NPPNB (NPTS+NBIN)
+
+int main(void)
+{
+	int i=0,k,nlim;
+	float adev,ave,curt,sdev,skew,vrnce,x,*data;
+
+	data=vector(1,NPPNB);
+	for (x=PI/NBIN;x<=PI;x+=PI/NBIN) {
+		nlim=(int) (0.5+sin(x)*PI/2.0*NPTS/NBIN);
+		for (k=1;k<=nlim;k++) data[++i]=x;
+	}
+	printf("moments of a sinusoidal distribution\n\n");
+	moment(data,i,&ave,&adev,&sdev,&vrnce,&skew,&curt);
+	printf("%39s %11s\n\n","calculated","expected");
+	printf("%s %17s %12.4f %12.4f\n","Mean :"," ",ave,PI/2.0);
+	printf("%s %4s %12.4f %12.4f\n",
+		"Average Deviation :"," ",adev,(PI/2.0)-1.0);
+	printf("%s %3s %12.4f %12.4f\n",
+		"Standard Deviation :"," ",sdev,0.683667);
+	printf("%s %13s %12.4f %12.4f\n",
+		"Variance :"," ",vrnce,0.467401);
+	printf("%s %13s %12.4f %12.4f\n",
+		"Skewness :"," ",skew,0.0);
+	printf("%s %13s %12.4f %12.4f\n",
+		"Kurtosis :"," ",curt,-0.806249);
+	free_vector(data,1,NPPNB);
+	return 0;
+}
+#undef NRANSI