add numerical recipes library

lib/nr/ansi/examples/xsncndn.c

@@ -0,0 +1,41 @@
+
+/* Driver for routine sncndn */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#define NRANSI
+#include "nr.h"
+#include "nrutil.h"
+
+#define MAXSTR 80
+
+int main(void)
+{
+	char txt[MAXSTR];
+	int i,nval;
+	float em,emmc,uu,val,sn,cn,dn;
+	FILE *fp;
+
+	if ((fp = fopen("fncval.dat","r")) == NULL)
+		nrerror("Data file fncval.dat not found\n");
+	fgets(txt,MAXSTR,fp);
+	while (strncmp(txt,"Jacobian Elliptic Function",26)) {
+		fgets(txt,MAXSTR,fp);
+		if (feof(fp)) nrerror("Data not found in fncval.dat\n");
+	}
+	fscanf(fp,"%d %*s",&nval);
+	printf("\n%s\n",txt);
+	printf("%4s %8s %16s %13s %15s %18s\n","mc","u","actual",
+		"sn","sn^2+cn^2","(mc)*(sn^2)+dn^2");
+	for (i=1;i<=nval;i++) {
+		fscanf(fp,"%f %f %f",&em,&uu,&val);
+		emmc=1.0-em;
+		sncndn(uu,emmc,&sn,&cn,&dn);
+		printf("%5.2f %8.2f %15.5f %15.5f %12.5f %14.5f\n",
+			emmc,uu,val,sn,(sn*sn+cn*cn),(em*sn*sn+dn*dn));
+	}
+	fclose(fp);
+	return 0;
+}
+#undef NRANSI