void solve(TString outFileName){ ROOT::Math::Minimizer* min = ROOT::Math::Factory::CreateMinimizer("Minuit2", "MIGRAD"); min->SetMaxFunctionCalls(1000000); min->SetTolerance(0.001); min->SetPrintLevel(10); ROOT::Math::Functor f(&totalDist,4); double step[4] = {0.01,0.01,.01,.01}; double variable[4] = { 0,0,50,0}; min->SetFunction(f); min->SetVariable(0,"x" ,variable[0], step[0]); min->SetVariable(1,"y" ,variable[1], step[1]); min->SetVariable(2,"z" ,variable[2], step[2]); min->SetVariable(3,"phi",variable[3], step[3]); // do the minimization min->Minimize(); const double *xs = min->X(); std::cout << "Minimum: f(" << xs[0] << "," << xs[1]<< "," << xs[2]<< "," << xs[3] << "): " << min->MinValue() << std::endl; setZ=xs[2]; ROOT::Math::Minimizer* min2 = ROOT::Math::Factory::CreateMinimizer("Minuit2", "MIGRAD"); min2->SetMaxFunctionCalls(1000000); min2->SetTolerance(0.001); min2->SetPrintLevel(10); ROOT::Math::Functor f2(&totalDistWithoutZ,3); double step2[3] = {0.01,0.01,.01}; double variable2[3] = { xs[0],xs[1],xs[3]}; min2->SetFunction(f2); min2->SetVariable(0,"x" ,variable2[0], step2[0]); min2->SetVariable(1,"y" ,variable2[1], step2[1]); min2->SetVariable(2,"phi",variable2[2], step2[2]); // do the minimization min2->Minimize(); const double *xs2 = min2->X(); std::cout << "Minimum: f(" << xs2[0] << "," << xs2[1]<< "," << xs2[2] << "): " << min2->MinValue() << std::endl; // // expected minimum is 0 // if ( min->MinValue() < 1.E-4 && f(xs) < 1.E-4) // std::cout << " converged to the right minimum" << std::endl; // else { // std::cout << " failed to converge !!!" << std::endl; // Error("NumericalMinimization","fail to converge"); // } }
void find_chisqMin() { chisq=0.; for(int i=0; i<numSpectra; i++) { // for more information see minimizer class documentation // https://root.cern.ch/root/html/ROOT__Math__Minimizer.html char minName[132] = "Minuit"; char algoName[132] = ""; // default conjugate gradient type method ROOT::Math::Minimizer* min = ROOT::Math::Factory::CreateMinimizer(minName, algoName); // set tolerance , etc... min->SetMaxFunctionCalls(1000000); // for Minuit min->SetMaxIterations(10000); // for GSL min->SetTolerance(0.001); min->SetPrintLevel(0); // set to 1 for more info // communication to the likelihood ratio function // (via global parameters) for(int j=0; j<S32K; j++) { expCurrent[j] = (double)expHist[spectrum[i]][j]; simCurrent[j] = (double)dOutHist[spectrum[i]][j]; } spCurrent = i; // create funciton wrapper for minmizer // a IMultiGenFunction type ROOT::Math::Functor lr(&lrchisq,3); // behaves best when these are small // starting point double variable[3] = {0.001,0.001,0.001}; // step size double step[3] = {0.0001,0.0001,0.0001}; min->SetFunction(lr); // Set pars for minimization min->SetVariable(0,"a0",variable[0],step[0]); min->SetVariable(1,"a1",variable[1],step[1]); min->SetVariable(2,"a2",variable[2],step[2]); // do the minimization min->Minimize(); // grab parameters from minimum const double *xs = min->X(); // print results /* std::cout << "Minimum: f(" << xs[0] << "," << xs[1] << "," << xs[2] << "): " */ /* << min->MinValue() << std::endl; */ // assuming 3 parameters // save pars for(int j=0;j<3;j++) aFinal[j][i] = xs[j]; // add to total chisq chisq += min->MinValue(); } }
/* Main part of macro */ void fitData( TGraphErrors *gdata , TF1* ffit , double *startval ) { cout << "\n***** fitData.C: Starting fitting procedure... *****" << endl; g_data_global = gdata; f_fit_global = ffit; if ( g_data_global == NULL ) { cout << "fitData.C: Did no find any data to fit." << endl; return NULL; } const char * minName = "Minuit2"; const char *algoName = "Migrad"; // create minimizer giving a name and a name (optionally) for the specific // algorithm // possible choices are: // minName algoName // Minuit /Minuit2 Migrad, Simplex,Combined,Scan (default is Migrad) // Minuit2 Fumili2 // Fumili // GSLMultiMin ConjugateFR, ConjugatePR, BFGS, // BFGS2, SteepestDescent // GSLMultiFit // GSLSimAn // Genetic ROOT::Math::Minimizer* min = ROOT::Math::Factory::CreateMinimizer(minName, algoName); /* Alternatice constructor for Minuit */ //ROOT::Minuit2::Minuit2Minimizer *min = new ROOT::Minuit2::Minuit2Minimizer(); //TMinuit *min = new TMinuit(); // set tolerance , etc... min->SetMaxFunctionCalls(1000000); // for Minuit/Minuit2 min->SetMaxIterations(10000); // for GSL min->SetTolerance(0.001); min->SetPrintLevel(1); // create funciton wrapper for minmizer // a IMultiGenFunction type ROOT::Math::Functor f(&Chi2_log,3); double step[3] = {0.1,0.1,10}; // starting point double variable[3] = { startval[0],startval[1],startval[2]}; // set function to minimize (this is the Chi2 function) min->SetFunction(f); // Set the free variables to be minimized! min->SetVariable(0,"x",variable[0], step[0]); min->SetVariable(1,"y",variable[1], step[1]); min->SetVariable(2,"z",variable[2], step[2]); // do the minimization min->Minimize(); /* set function parameters to best fit results */ const double *xs = min->X(); f_fit_global->SetParameter(0, xs[0]); f_fit_global->SetParameter(1, xs[1]); f_fit_global->SetParameter(2, xs[2]); /* Print summaries of minimization process */ std::cout << "Minimum: f(" << xs[0] << ", " << xs[1] << ", " << xs[2] << "): " << min->MinValue() << std::endl; // expected minimum is 0 if ( min->MinValue() < 1.E-4 && f(xs) < 1.E-4) std::cout << "Minimizer " << minName << " - " << algoName << " converged to the right minimum" << std::endl; else { std::cout << "Minimizer " << minName << " - " << algoName << " failed to converge !!!" << std::endl; Error("NumericalMinimization","fail to converge"); } /* Get degrees of freedom NDF */ unsigned ndf = 0; /* get range of function used for fit */ double fit_min, fit_max; f_fit_global->GetRange(fit_min,fit_max); /* count data points in range of function */ for ( int p = 0; p < g_data_global->GetN(); p++ ) { if ( g_data_global->GetX()[p] >= fit_min && g_data_global->GetX()[p] <= fit_max ) { ndf++; } } ndf -= 3; // 3 parameters in fit cout << "Degrees of freedom: " << ndf << " --> chi2 / NDF = " << min->MinValue() / ndf << endl; /* Get error covariance matrix from minimizer */ TMatrixD matrix0(3,3); for ( unsigned i = 0; i < 3; i++ ) { for ( unsigned j = 0; j < 3; j++ ) { matrix0[i][j] = min->CovMatrix(i,j); } } matrix0.Print(); /* Get minos error */ double par0_minos_error_up = 0; double par0_minos_error_low = 0; double par1_minos_error_up = 0; double par1_minos_error_low = 0; double par2_minos_error_up = 0; double par2_minos_error_low = 0; min->GetMinosError( 0, par0_minos_error_low, par0_minos_error_up ); min->GetMinosError( 1, par1_minos_error_low, par1_minos_error_up ); min->GetMinosError( 2, par2_minos_error_low, par2_minos_error_up ); cout << "Minos uncertainty parameter 0: up = " << par0_minos_error_up << ", low = " << par0_minos_error_low << endl; cout << "Minos uncertainty parameter 1: up = " << par1_minos_error_up << ", low = " << par1_minos_error_low << endl; cout << "Minos uncertainty parameter 2: up = " << par2_minos_error_up << ", low = " << par2_minos_error_low << endl; /* Plot chi2 */ /* sigmas symmetric from covariance matrix */ //double sigmas[6] = {sqrt(matrix0[0][0]), sqrt(matrix0[0][0]), sqrt(matrix0[1][1]), sqrt(matrix0[1][1]), sqrt(matrix0[2][2]), sqrt(matrix0[2][2])}; /* sigmas asymmetric from minos */ double sigmas[6] = {par0_minos_error_low, par0_minos_error_up, par1_minos_error_low, par1_minos_error_up, par2_minos_error_low, par2_minos_error_up}; plotChi2( g_data_global, f_fit_global, 3, sigmas ); /* Draw contour plots */ TGraph2D* gcontour3D = plotContour( min , 3 , ndf ); /* Find error boundaries */ TF1* flow = (TF1*)f_fit_global->Clone("flow"); TF1* fup = (TF1*)f_fit_global->Clone("fup"); flow->SetRange(0,100000); flow->SetLineColor(kBlue); flow->SetLineStyle(2); fup->SetRange(0,100000); fup->SetLineColor(kBlue); fup->SetLineStyle(2); findErrorBounds( f_fit_global, flow, fup, gcontour3D ); /* plot residuals data w.r.t. fit */ plotResiduals( g_data_global, f_fit_global, flow, fup ); /* Draw data, best fit, and 1-sigma band */ TCanvas *cfit = new TCanvas(); g_data_global->Draw("AP"); //f_fit_global->SetRange(0,4000); f_fit_global->Draw("same"); flow->Draw("same"); fup->Draw("same"); cfit->Print("new_FitResult.png"); /* Fit Extrapolation */ double t_extrapolate_months = 6; double t_extrapolate_s = t_extrapolate_months * 30 * 24 * 60 * 60; cout << "Extrapolation to " << t_extrapolate_months << " months: " << ffit->Eval( t_extrapolate_s ) << " , up: " << fup->Eval( t_extrapolate_s ) - ffit->Eval( t_extrapolate_s ) << " , low: " << flow->Eval( t_extrapolate_s ) - ffit->Eval( t_extrapolate_s ) << endl; return f_fit_global; }
int NumericalMinimization(const char * minName = "Minuit2", const char *algoName = "" , int randomSeed = -1) { // create minimizer giving a name and a name (optionally) for the specific // algorithm // possible choices are: // minName algoName // Minuit /Minuit2 Migrad, Simplex,Combined,Scan (default is Migrad) // Minuit2 Fumili2 // Fumili // GSLMultiMin ConjugateFR, ConjugatePR, BFGS, // BFGS2, SteepestDescent // GSLMultiFit // GSLSimAn // Genetic ROOT::Math::Minimizer* minimum = ROOT::Math::Factory::CreateMinimizer(minName, algoName); // set tolerance , etc... minimum->SetMaxFunctionCalls(1000000); // for Minuit/Minuit2 minimum->SetMaxIterations(10000); // for GSL minimum->SetTolerance(0.001); minimum->SetPrintLevel(1); // create function wrapper for minimizer // a IMultiGenFunction type ROOT::Math::Functor f(&RosenBrock,2); double step[2] = {0.01,0.01}; // starting point double variable[2] = { -1.,1.2}; if (randomSeed >= 0) { TRandom2 r(randomSeed); variable[0] = r.Uniform(-20,20); variable[1] = r.Uniform(-20,20); } minimum->SetFunction(f); // Set the free variables to be minimized ! minimum->SetVariable(0,"x",variable[0], step[0]); minimum->SetVariable(1,"y",variable[1], step[1]); // do the minimization minimum->Minimize(); const double *xs = minimum->X(); std::cout << "Minimum: f(" << xs[0] << "," << xs[1] << "): " << minimum->MinValue() << std::endl; // expected minimum is 0 if ( minimum->MinValue() < 1.E-4 && f(xs) < 1.E-4) std::cout << "Minimizer " << minName << " - " << algoName << " converged to the right minimum" << std::endl; else { std::cout << "Minimizer " << minName << " - " << algoName << " failed to converge !!!" << std::endl; Error("NumericalMinimization","fail to converge"); } return 0; }