add numerical recipes library

lib/nr/ansi/examples/xbessjy.c

@@ -0,0 +1,40 @@
+
+/* Driver for routine bessjy */
+
+#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 rj,ry,rjp,ryp,x,xnu,xrj,xry,xrjp,xryp;
+	FILE *fp;
+
+	if ((fp = fopen("fncval.dat","r")) == NULL)
+		nrerror("Data file fncval.dat not found\n");
+	fgets(txt,MAXSTR,fp);
+	while (strncmp(txt,"Ordinary Bessel Functions",25)) {
+		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("%5s %7s\n%14s %16s %17s %16s\n%14s %16s %17s %16s\n",
+		"xnu","x","rj","ry","rjp","ryp","xrj","xry","xrjp","xryp");
+	for (i=1;i<=nval;i++) {
+		fscanf(fp,"%f %f %f %f %f %f",&xnu,&x,&rj,&ry,&rjp,&ryp);
+		bessjy(x,xnu,&xrj,&xry,&xrjp,&xryp);
+		printf("%5.2f %5.2f\n\t%16.6e %16.6e %16.6e %16.6e\n",xnu,x,rj,ry,rjp,ryp);
+		printf("\t%16.6e %16.6e %16.6e %16.6e\n",xrj,xry,xrjp,xryp);
+	}
+	fclose(fp);
+	return 0;
+}
+#undef NRANSI