add numerical recipes library

lib/nr/ansi/examples/xperiod.c

@@ -0,0 +1,43 @@
+
+/* Driver for routine period */
+
+#include <stdio.h>
+#include <math.h>
+#define NRANSI
+#include "nr.h"
+#include "nrutil.h"
+
+#define NP 90
+#define NPR 11
+#define TWOPI 6.2831853
+
+int main(void)
+{
+	long idum=(-4);
+	int j=0,jmax,n,nout;
+	float prob,*px,*py,*x,*y;
+
+	x=vector(1,NP);
+	y=vector(1,NP);
+	px=vector(1,2*NP);
+	py=vector(1,2*NP);
+	for (n=1;n<=NP+10;n++) {
+		if (n != 3 && n != 4 && n != 6 && n != 21 &&
+			n != 38 && n != 51 && n != 67 && n != 68 &&
+			n != 83 && n != 93) {
+			x[++j]=n;
+			y[j]=0.75*cos(0.6*x[j])+gasdev(&idum);
+		}
+	}
+	period(x,y,j,4.0,1.0,px,py,2*NP,&nout,&jmax,&prob);
+	printf("period results for test signal (cos(0.6x) + noise):\n");
+	printf("nout,jmax,prob=%d %d %12.6g\n",nout,jmax,prob);
+	for (n=LMAX(1,jmax-NPR/2);n<=LMIN(nout,jmax+NPR/2);n++)
+		printf("%d %12.6f %12.6f\n",n,TWOPI*px[n],py[n]);
+	free_vector(py,1,2*NP);
+	free_vector(px,1,2*NP);
+	free_vector(y,1,NP);
+	free_vector(x,1,NP);
+	return 0;
+}
+#undef NRANSI