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// @(#)root/minuit2:$Id$
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// Author: L. Moneta 12/2005
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/**
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test of a pure minimization passing a user FCN class directly to the
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TFitterMinuit
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*/
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#include "TH1.h"
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#include "TF1.h"
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#include "TRandom3.h"
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#include "TVirtualFitter.h"
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#include "TStyle.h"
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#include "Minuit2/FCNBase.h"
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#include "TFitterMinuit.h"
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#include "TSystem.h"
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#include "TStopwatch.h"
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#include <vector>
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#include <iostream>
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class MyFCN : public ROOT::Minuit2::FCNBase {
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public:
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MyFCN(double a = 100, double b = 1) : fA(a), fB(b) {}
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double operator() (const std::vector<double> & x) const {
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// Rosebrock function
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return fA*(x[1] - x[0]*x[0])*(x[1] - x[0]*x[0]) + fB*(1 - x[0])*(1 - x[0]);
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}
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double Up() const { return 1.; }
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private:
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double fA;
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double fB;
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};
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int testMinimize() {
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gSystem->Load("libMinuit2");
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TFitterMinuit * minuit = new TFitterMinuit();
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MyFCN fcn;
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minuit->SetMinuitFCN(&fcn);
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// starting values
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double startX = -1.2;
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double startY = 1.0;
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// if not limited (vhigh <= vlow)
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minuit->SetParameter(0,"x",startX,0.1,0,0);
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minuit->SetParameter(1,"y",startY,0.1,0,0);
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minuit->SetPrintLevel(3);
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// create Minimizer (default is Migrad)
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minuit->CreateMinimizer();
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int iret = minuit->Minimize();
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if (iret != 0) {
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return iret;
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}
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std::cout << "\nTest performances........\n\n";
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// test performances
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int nMin = 10000;
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TStopwatch w;
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w.Start();
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for (int i = 0; i < nMin; ++i) {
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minuit->Clear();
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// reset -everything
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//minuit->SetMinuitFCN(&fcn);
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minuit->SetParameter(0,"x",startX,0.1,0,0);
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minuit->SetParameter(1,"y",startY,0.1,0,0);
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minuit->SetPrintLevel(0);
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// create Minimizer (default is Migrad)
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minuit->CreateMinimizer();
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iret = minuit->Minimize();
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if (iret != 0) {
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std::cout << "Minimization failed - exit " ;
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return iret;
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}
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}
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w.Stop();
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std::cout << "\nTime: \t" << w.RealTime() << " , " << w.CpuTime() << std::endl;
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return 0;
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}
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#ifndef __CINT__
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int main() {
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int iret = testMinimize();
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if (iret != 0) {
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std::cerr << "ERROR: Minimize test failed !" << std::endl;
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return iret;
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}
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return 0;
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}
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#endif
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