add numerical recipes library

lib/nr/cpp/recipes/dlinmin.cpp

@@ -0,0 +1,36 @@
+#include "nr.h"
+
+int ncom;
+DP (*nrfunc)(Vec_I_DP &);
+void (*nrdfun)(Vec_I_DP &, Vec_O_DP &);
+Vec_DP *pcom_p,*xicom_p;
+
+void NR::dlinmin(Vec_IO_DP &p, Vec_IO_DP &xi, DP &fret, DP func(Vec_I_DP &),
+	void dfunc(Vec_I_DP &, Vec_O_DP &))
+{
+	const DP TOL=2.0e-8;
+	int j;
+	DP xx,xmin,fx,fb,fa,bx,ax;
+
+	int n=p.size();
+	ncom=n;
+	pcom_p=new Vec_DP(n);
+	xicom_p=new Vec_DP(n);
+	nrfunc=func;
+	nrdfun=dfunc;
+	Vec_DP &pcom=*pcom_p,&xicom=*xicom_p;
+	for (j=0;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=dbrent(ax,xx,bx,f1dim,df1dim,TOL,xmin);
+	for (j=0;j<n;j++) {
+		xi[j] *= xmin;
+		p[j] += xi[j];
+	}
+	delete xicom_p;
+	delete pcom_p;
+}