add numerical recipes library

lib/nr/ansi/examples/xfitexy.c

@@ -0,0 +1,62 @@
+
+/* Driver for routine fitexy */
+
+#include <stdio.h>
+#include <math.h>
+#define NRANSI
+#include "nr.h"
+#include "nrutil.h"
+
+#define NPT 30
+
+int main(void)
+{
+	long idum=(-1);
+	int j;
+	float a,b,chi2,q,sa,sb,siga,sigb;
+	float *x,*y,*dx,*dy,*dz;
+
+	x=vector(1,NPT);
+	y=vector(1,NPT);
+	dx=vector(1,NPT);
+	dy=vector(1,NPT);
+	dz=vector(1,NPT);
+	for (j=1;j<=NPT;j++) {
+		dx[j]=0.1+ran1(&idum);
+		dy[j]=0.1+ran1(&idum);
+		dz[j]=0.0;
+		x[j]=10.0+10.0*gasdev(&idum);
+		y[j]=2.0*x[j]-5.0+dy[j]*gasdev(&idum);
+		x[j] += dx[j]*gasdev(&idum);
+	}
+	printf("Values of a,b,siga,sigb,chi2,q:\n");
+	printf("Fit with x and y errors gives:\n");
+	fitexy(x,y,NPT,dx,dy,&a,&b,&siga,&sigb,&chi2,&q);
+	printf("%11.6f %11.6f %11.6f %11.6f %11.6f %11.6f\n\n",
+		a,b,siga,sigb,chi2,q);
+	printf("Setting x errors to zero gives:\n");
+	fitexy(x,y,NPT,dz,dy,&a,&b,&siga,&sigb,&chi2,&q);
+	printf("%11.6f %11.6f %11.6f %11.6f %11.6f %11.6f\n",
+		a,b,siga,sigb,chi2,q);
+	printf("...to be compared with fit result:\n");
+	fit(x,y,NPT,dy,1,&a,&b,&siga,&sigb,&chi2,&q);
+	printf("%11.6f %11.6f %11.6f %11.6f %11.6f %11.6f\n\n",
+		a,b,siga,sigb,chi2,q);
+	printf("Setting y errors to zero gives:\n");
+	fitexy(x,y,NPT,dx,dz,&a,&b,&siga,&sigb,&chi2,&q);
+	printf("%11.6f %11.6f %11.6f %11.6f %11.6f %11.6f\n",
+		a,b,siga,sigb,chi2,q);
+	printf("...to be compared with fit result:\n");
+	fit(y,x,NPT,dx,1,&a,&b,&siga,&sigb,&chi2,&q);
+	sa=sqrt(siga*siga+SQR(sigb*(a/b)))/b;
+	sb=sigb/(b*b);
+	printf("%11.6f %11.6f %11.6f %11.6f %11.6f %11.6f\n",
+		-a/b,1.0/b,sa,sb,chi2,q);
+	free_vector(dz,1,NPT);
+	free_vector(dy,1,NPT);
+	free_vector(dx,1,NPT);
+	free_vector(y,1,NPT);
+	free_vector(x,1,NPT);
+	return 0;
+}
+#undef NRANSI