add numerical recipes library

lib/nr/ansi/examples/xfgauss.c

@@ -0,0 +1,45 @@
+
+/* Driver for routine fgauss */
+
+#include <stdio.h>
+#include <math.h>
+#define NRANSI
+#include "nr.h"
+#include "nrutil.h"
+
+#define NPT 3
+#define NLIN 2
+#define NA 3*NLIN
+
+int main(void)
+{
+	int i,j;
+	float e1,e2,f,x,y;
+	static float a[NA+1]={0.0,3.0,0.2,0.5,1.0,0.7,0.3};
+	float dyda[NA+1],df[NA+1];
+
+	printf("\n%6s %8s %8s %7s %7s %7s %7s %7s\n",
+		"x","y","dyda1","dyda2","dyda3","dyda4","dyda5","dyda6");
+	for (i=1;i<=NPT;i++) {
+		x=0.3*i;
+		fgauss(x,a,&y,dyda,NA);
+		e1=exp(-SQR((x-a[2])/a[3]));
+		e2=exp(-SQR((x-a[5])/a[6]));
+		f=a[1]*e1+a[4]*e2;
+		df[1]=e1;
+		df[4]=e2;
+		df[2]=a[1]*e1*2.0*(x-a[2])/(a[3]*a[3]);
+		df[5]=a[4]*e2*2.0*(x-a[5])/(a[6]*a[6]);
+		df[3]=a[1]*e1*2.0*SQR(x-a[2])/(a[3]*a[3]*a[3]);
+		df[6]=a[4]*e2*2.0*SQR(x-a[5])/(a[6]*a[6]*a[6]);
+		printf("from FGAUSS\n");
+		printf("%8.4f %8.4f",x,y);
+		for (j=1;j<=6;j++) printf("%8.4f",dyda[j]);
+		printf("\nindependent calc.\n");
+		printf("%8.4f %8.4f",x,f);
+		for (j=1;j<=6;j++) printf("%8.4f",df[j]);
+		printf("\n\n");
+	}
+	return 0;
+}
+#undef NRANSI