add numerical recipes library

lib/nr/ansi/recipes/linmin.c

@@ -0,0 +1,39 @@
+
+#define NRANSI
+#include "nrutil.h"
+#define TOL 2.0e-4
+
+int ncom;
+float *pcom,*xicom,(*nrfunc)(float []);
+
+void linmin(float p[], float xi[], int n, float *fret, float (*func)(float []))
+{
+	float brent(float ax, float bx, float cx,
+		float (*f)(float), float tol, float *xmin);
+	float f1dim(float x);
+	void mnbrak(float *ax, float *bx, float *cx, float *fa, float *fb,
+		float *fc, float (*func)(float));
+	int j;
+	float xx,xmin,fx,fb,fa,bx,ax;
+
+	ncom=n;
+	pcom=vector(1,n);
+	xicom=vector(1,n);
+	nrfunc=func;
+	for (j=1;j<=n;j++) {
+		pcom[j]=p[j];
+		xicom[j]=xi[j];
+	}
+	ax=0.0;
+	xx=1.0;
+	mnbrak(&ax,&xx,&bx,&fa,&fx,&fb,f1dim);
+	*fret=brent(ax,xx,bx,f1dim,TOL,&xmin);
+	for (j=1;j<=n;j++) {
+		xi[j] *= xmin;
+		p[j] += xi[j];
+	}
+	free_vector(xicom,1,n);
+	free_vector(pcom,1,n);
+}
+#undef TOL
+#undef NRANSI