JetFitAnalyzer/src/jetfit.cpp

/* jetfit.cpp - Package to fit multi-Gaussian distributions to histograms
 * rewrite after accidental deletion 07-24-09
 * Author: David Nisson
 */

#include <cstdlib>
#include <cmath>
#include <ctime>
#include <cstdio>
#include <cstring>
#include <cctype>
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <limits>
#include <exception>

#include <TMinuit.h>
#include <TH1.h>
#include <TH2.h>
#include <TF2.h>
#include <TRandom3.h>
#include <Rtypes.h>
#include <TFormula.h>
#include <TSystem.h>

#include "UserCode/JetFitAnalyzer/interface/jetfit.h"

#define PI 3.141592653

#define MAX_GAUSS 3

using namespace std;

namespace jetfit {
  // configurable options
  bool ignorezero = false; // ignore zero bins when fitting
  
  int ngauss; // number of Gaussians in current model
  
  struct histo {
    vector< vector<double> > bins;
    double Xlo, Xhi, Ylo, Yhi;
  } energy;


  model_def *mdef;

  model_def& curr_model_def() {
    return *mdef;
  }

  void set_model_def(model_def *_mdef) {
    mdef = _mdef;
  }

  int get_ngauss() {
    return ngauss;
  }
  
  void set_ngauss(int _ngauss) {
    ngauss = _ngauss;
  }

  // fit function
  double fit_fcn(double x, double y, double *xval) {
    int npar_indiv = mdef->get_formula()->GetNpar();
    double val = 0.0;
    for (int i = 0; i < ngauss; i++) {
      mdef->get_formula()->SetParameters(xval + i*npar_indiv);
      val += mdef->get_formula()->Eval(x, y);
    }
    return val;
  }

  // TF2-compatible fit function
  double fit_fcn_TF2(double *x, double *pval) {
    double val = fit_fcn(x[0], x[1], pval);
    return val;
  }

  // Integral of model formula / chisquare sigma
  double formula_int(double xlo, double xhi, double ylo, double yhi,
                     double *pval, double XbinSize, double YbinSize,
                     double *xval) {
    double xstep = (xhi - xlo) / static_cast<double>(20);
    double ystep = (yhi - ylo) / static_cast<double>(20);

    double fsum = 0.0;
    double pval_old[256];
    int npar = mdef->get_formula()->GetNpar();
    if (npar > 256) {
      cerr << "Parameter overload" << endl;
      return 0.0;
    }
    mdef->get_formula()->GetParameters(pval_old);
    mdef->get_formula()->SetParameters(pval);

    for (int i = 0; i < 20; i++) {
      for (int j = 0; j < 20; j++) {
        double x = (static_cast<double>(i) + 0.5)*xstep + xlo;
        double y = (static_cast<double>(j) + 0.5)*ystep + ylo;
        double sig_cut = 1.0e-5;
        double nu = XbinSize * YbinSize * fit_fcn(x, y, xval);
        double sigma = fabs(mdef->chisquare_error(0.0)) < sig_cut
          ? sig_cut : mdef->chisquare_error(0.0);

        fsum += pow(xstep * ystep * mdef->get_formula()->Eval(x, y), 2.0)
          / sigma / sigma;
      }
    }

    mdef->get_formula()->SetParameters(pval_old);
    return fsum;
  }

  // MINUIT objective function 
  void fcn(int &npar, double *grad, double &fcnval, double *xval, int iflag)
  {
    double chisquare = 0.0;
    double XbinSize = (energy.Xhi - energy.Xlo)
      / static_cast<double>(energy.bins.size());
    double YbinSize = (energy.Yhi - energy.Ylo)
      / static_cast<double>(energy.bins.at(0).size());
    try {
      // add errors in data points in histogram
      for (int i = 0; i < energy.bins.size(); i++) {
        for (int j = 0; j < energy.bins.at(i).size(); j++) {
          double x = (static_cast<double>(i) + 0.5) * (energy.Xhi - energy.Xlo)
            / static_cast<double>(energy.bins.size()) + energy.Xlo;
          double y = (static_cast<double>(j) + 0.5) * (energy.Yhi - energy.Ylo)
            / static_cast<double>(energy.bins.at(i).size()) + energy.Ylo;
          double nu = fit_fcn(x, y, xval) * XbinSize * YbinSize;
          double sig_cut = 1.0e-5;
          if (fabs(mdef->chisquare_error(energy.bins.at(i).at(j))) > sig_cut || !ignorezero) {
            chisquare += pow(energy.bins.at(i).at(j) - nu, 2.0) 
              / pow(mdef->chisquare_error(energy.bins.at(i).at(j)), 2.0);
          }
          else {
            chisquare += pow(energy.bins.at(i).at(j) - nu, 2.0) 
              / pow(sig_cut, 2.0);
          }
        }
      }
      
      // add errors due to Gaussians outside histogram
      double eps = 0.01; // accuracy set for this function
      for (int i = 0; i < ngauss; i++) {
        double *pval = xval+i*(mdef->get_formula()->GetNpar());
        double par_x = pval[mdef->get_indiv_max_x()];
        double par_y = pval[mdef->get_indiv_max_y()];
        double par_sig = pval[3];
        double cutoff_rad = sqrt(-log(eps * 2.0 * PI * par_sig * par_sig
          / pval[0]) * 2.0 * par_sig * par_sig);

        bool left = par_x < energy.Xlo + cutoff_rad;
        bool right = par_x > energy.Xhi - cutoff_rad;
        bool top = par_y > energy.Yhi - cutoff_rad;
        bool bottom = par_y < energy.Ylo + cutoff_rad;

        if (left) {
          double xlo = par_x - cutoff_rad;
          double xhi = energy.Xlo;
          double ylo = energy.Ylo;
          double yhi = energy.Yhi;
          chisquare += 2.0*formula_int(xlo, xhi, ylo, yhi, pval,
                                   XbinSize, YbinSize, xval);
        }
        if (right) {
          double xlo = energy.Xhi;
          double xhi = par_x + cutoff_rad;
          double ylo = energy.Ylo;
          double yhi = energy.Yhi;
          chisquare += 2.0*formula_int(xlo, xhi, ylo, yhi, pval,
                                   XbinSize, YbinSize, xval);
        }
        if (top) {
          double xlo = left ? par_x - cutoff_rad : energy.Xlo;
          double xhi = right ? par_x + cutoff_rad : energy.Xhi;
          double ylo = energy.Yhi;
          double yhi = par_y + cutoff_rad;
          chisquare += 2.0*formula_int(xlo, xhi, ylo, yhi, pval,
                                   XbinSize, YbinSize, xval);
        }
        if (bottom) {
          double xlo = left ? par_x - cutoff_rad : energy.Xlo;
          double xhi = right ? par_x + cutoff_rad : energy.Xhi;
          double ylo = par_y - cutoff_rad;
          double yhi = energy.Ylo;
          chisquare += 2.0*formula_int(xlo, xhi, ylo, yhi, pval,
                                   XbinSize, YbinSize, xval);
        }
      }
      
      fcnval = chisquare;
    }
    catch (exception ex) {
      cerr << "Exception in jetfit::fcn" << endl;
    }
  }

  bool get_ignorezero() {
    return ignorezero;
  }

  void set_ignorezero(bool _iz) {
    ignorezero = _iz;
  }

  TFormula * model_def::get_formula() {
    return indiv_formula;
  }

  void model_def::set_formula(TFormula *new_formula) {
    indiv_formula = new_formula;
  }

  void model_def::get_indiv_par(int i, string &name, double &start, double &step,
                     double &lo, double &hi) {
    try {
      name = indiv_par_names.at(i);
      start = indiv_par_starts.at(i);
      step = indiv_par_start_steps.at(i);
      lo = indiv_par_lo.at(i);
      hi = indiv_par_hi.at(i);
    } catch (exception ex) {
      cerr << "exception in jetfit::model_def::get_indiv_par" << endl;
    }
  }

  void model_def::set_indiv_par(int i, string name, double start, double step,
                     double lo, double hi) {
    if (indiv_par_names.size() < i+1) {
      indiv_par_names.resize(i+1);
      indiv_par_starts.resize(i+1);
      indiv_par_start_steps.resize(i+1);
      indiv_par_lo.resize(i+1);
      indiv_par_hi.resize(i+1);
    }
    try {
      indiv_par_names.at(i) = name;
      indiv_par_starts.at(i) = start;
      indiv_par_start_steps.at(i) = step;
      indiv_par_lo.at(i) = lo;
      indiv_par_hi.at(i) = hi;
    }
    catch (exception ex) {
      cerr << "exception in jetfit::model_def::set_indiv_par" << endl;
    }
  }

  int model_def::get_indiv_max_E() {
    return indiv_max_E;
  }

  void model_def::set_indiv_max_E(int _new_max_E) {
    indiv_max_E = _new_max_E;
  }

  int model_def::get_indiv_max_x() {
    return indiv_max_x;
  }

  void model_def::set_indiv_max_x(int new_max_x) {
    indiv_max_x = new_max_x;
  }

  int model_def::get_indiv_max_y() {
    return indiv_max_y;
  }

  void model_def::set_indiv_max_y(int new_max_y) {
    indiv_max_y = new_max_y;
  }

  unsigned model_def::get_n_special_par_sets() {
    return special_par_starts.size();
  }

  void model_def::get_special_par(int g, int i, double &pstart,
                                  double &perr, double &plo, double &phi) {
    try {
      pstart = special_par_starts.at(g).at(i);
      perr = special_par_start_steps.at(g).at(i);
      plo = special_par_lo.at(g).at(i);
      phi = special_par_hi.at(g).at(i);
    } catch (exception ex) {
      cerr << "Exception in model_def::get_special_par" << endl;
    }
  }

  void model_def::set_special_par(int g, int i, double pstart,
                                  double perr, double plo, double phi) {
    if (g+1 > special_par_starts.size()) {
      special_par_starts.resize(g+1);
      special_par_start_steps.resize(g+1);
      special_par_lo.resize(g+1);
      special_par_hi.resize(g+1);
    }

    try {
      if (i+1 > special_par_starts.at(g).size()) {
        special_par_starts.at(g).resize(i+1);
        special_par_start_steps.at(g).resize(i+1);
        special_par_lo.at(g).resize(i+1);
        special_par_hi.at(g).resize(i+1);
      }

      special_par_starts.at(g).at(i) = pstart;
      special_par_start_steps.at(g).at(i) = perr;
      special_par_lo.at(g).at(i) = plo;
      special_par_hi.at(g).at(i) = phi;
    }
    catch (exception ex) {
      cerr << "exception in jetfit::model_def::set_special_par" << endl;
    }
  }

  // translation of CERN's ERFC function
  double erfc(double x) {
    bool lef = false;
    double p2[5], q2[5];

    const double z1 = 1.0, hf = z1/2.0, c1 = 0.56418958;
    const double vmax = 7.0;
    const double switch_ = 4.0;

    double p10 = 3.6767877, q10 = 3.2584593, p11 = -9.7970465e-2;
    p2[0] = 7.3738883;
    q2[0] = 7.3739609;
    p2[1] = 6.8650185;
    q2[1] = 1.5184908e1;
    p2[2] = 3.0317993;
    q2[2] = 1.2795530e1;
    p2[3] = 5.6316962e-1;
    q2[3] = 5.3542168;
    p2[4] = 4.3187787e-5;
    q2[4] = 1.0;

    double p30 = -1.2436854e-1, q30 = 4.4091706e-1, p31 = -9.6821036e-2;

    double v = fabs(x);
    double y, h, hc, ap, aq;
    if (v < hf) {
      y = v*v;
      h = x*(p10 + p11*y)/(q10 + y);
      hc = 1.0 - h;
    }
    else {
      if (v < switch_) {
        ap = p2[4];
        aq = q2[4];
        for (int i = 3; i >= 0; i--) {
          ap = p2[i] + v*ap;
          aq = q2[i] + v*aq;
        }
        hc = exp(-v*v)*ap/aq;
        h = 1.0 - hc;
      }
      else if (v < vmax) {
        y = 1/v/v;
        hc = exp(-v*v)*(c1 + y*(p30 + p31*y)/(q30 + y))/v;
        h = 1.0 - hc;
      }
      // for very big values we can save us any calculation
      // and the FP-exceptions from exp
      else {
        h = 1.0;
        hc = 0.0;
      }
      if (x < 0) {
        h = -h;
        hc = 2.0 - hc;
      }
    }
    if (lef) {
      return h;
    }
    else {
      return hc;
    }
  }

  // translation of CERN's PROB function
  double prob(double x, int n) {
    const char *name = "PROB";
    char errtxt[80];

    const double r1 = 1.0,
      hf = r1/2.0, th = r1/3.0, f1 = 2.0*r1/9.0;
    const double c1 = 1.128379167095513;
    const int nmax = 300;
    // maximum chi2 per df for df >= 2., if chi2/df > chipdf prob=0
    const double chipdf = 100.0;
    const double xmax = 174.673, xmax2 = 2.0*xmax;
    const double xlim = 24.0;
    const double eps = 1e-30;

    double y = x;
    double u = hf*y;
    double h, w, s, t, fi, e;
    int m;
    if (n < 0) {
      h = 0.0;
      sprintf(errtxt, "n = %d < 1", n);
      cerr << "PROB: G100.1: "<<errtxt;
    }
    else if (y < 0.0) {
      h = 0.0;
      sprintf(errtxt, "x = %f < 0", n);
      cerr << "PROB: G100.2: "<<errtxt;
    }
    else if (y == 0.0 || n/20 > y) {
      h = 1.0;
    }
    else if (n == 1) {
      w = sqrt(u);
      if (w < xlim) {
        h = erfc(w);
      }
      else {
        h = 0.0;
      }
    }
    else if (n > nmax) {
      s = r1 / ((double)n);
      t = f1 * s;
      w = (pow(y*s, th) - (1.0 - t)) / sqrt(2.0*t);
      if (w < -xlim) {
        h = 1.0;
      }
      else if (w < xlim) {
        h = hf * erfc(w);
      }
      else {
        h = 0.0;
      }
    }
    else {
      m = n/2;
      if (u < xmax2 && (y/n) <= chipdf) {
        s = exp(-hf*u);
        t = s;
        e = s;
        if (2*m == n) {
          fi = 0.0;
          for (int i = 1; i < m; i++) {
            fi += 1.0;
            t = u*t/fi;
            s += t;
          }
          h = s*e;
        }
        else {
          fi = 1.0;
          for (int i = 1; i < m; i++) {
            fi += 2.0;
            t = t*y/fi;
            s += t;
          }
          w = sqrt(u);
          if (w < xlim) {
            h = c1*w*s*e + erfc(w);
          }
          else {
            h = 0.0;
          }
        }
      }
      else {
        h = 0.0;
      }
    }
    if (h > eps) {
      return h;
    }
    else {
      return 0.0;
    }
  }
 
  void fill_histo_with_vec(TH2 *hist, vector< vector<double> > &vec) {
    for (int i = 0; i < vec.size(); i++) {
      for (int j = 0; j < vec[i].size(); j++) {
        hist->SetBinContent(i+1, j+1, vec[i][j]);
      }
    }
  }

  void par_init(TH2 *hist, TMinuit *gMinuit, vector<TString> &pars,
                double *pval, double *perr, double *plo, double *phi,
                int npar, results r) {
    int npar1 = npar - mdef->get_formula()->GetNpar();
    bool init_spec_pars = false;
    if (ngauss <= mdef->get_n_special_par_sets()) {
      init_spec_pars = true;
      for (int k = 0; k < ngauss; k++) {
        int ipar0 = k*mdef->get_formula()->GetNpar(); // index of indiv par 0
        for (int l = 0; l < mdef->get_formula()->GetNpar(); l++) {
          int ipar = ipar0 + l;
          if (ipar < npar)
            mdef->get_special_par(k, l, pval[ipar], perr[ipar], plo[ipar],
                                 phi[ipar]);
          else
            cerr << "WARNING: Attempt to set parameter out of index range!"
                 << endl;
        }
      }
    }
    else {
      double XbinSize = (energy.Xhi - energy.Xlo)
        / static_cast<double>(energy.bins.size());
      double YbinSize = (energy.Xhi - energy.Xlo)
        / static_cast<double>(energy.bins.at(0).size());
      vector< vector<double> > sub_energy(energy.bins.size());
      double max_sub, max_x = 0.0, max_y = 0.0;
      double pval_other[256];
      max_sub = -(numeric_limits<double>::max());
      for (int i = 0; i < energy.bins.size(); i++) {
        sub_energy[i].resize(energy.bins[i].size());
        for (int j = 0; j < energy.bins[i].size(); j++) {
          double x = static_cast<double>(i)*(energy.Xhi - energy.Xlo)
            / static_cast<double>(energy.bins.size()) + energy.Xlo;
          double y = static_cast<double>(j)*(energy.Yhi - energy.Ylo)
            / static_cast<double>(energy.bins[i].size()) + energy.Ylo;
          if (ngauss > 1) {
            // subtract integral of fit function
            try {
              int npval_other = r.pval.at(r.pval.size()-1).size();
              if (npval_other > 256) {
                cerr << "Parameter overload" << endl;
                return;
              }
              for (int k = 0; k < npval_other; k++) {
                pval_other[k] = r.pval[r.pval.size()-1][k];
              }
              ngauss--;
              double nu = fit_fcn(x, y, pval_other) * XbinSize * YbinSize;
              ngauss++;
              sub_energy[i][j] = energy.bins[i][j] - nu;
            }
            catch (exception ex) {
              cerr << "Exception in par_init" << endl;
            }
          }
          else {
            sub_energy[i][j] = energy.bins[i][j];
          }
        }
      }
      TH2D *hist_sub = new TH2D("hist_sub", "Subtracted histo",
                                sub_energy.size(), energy.Xlo,
                                energy.Xhi,
                                sub_energy[0].size(), energy.Ylo,
                                energy.Yhi);
      fill_histo_with_vec(hist_sub, sub_energy);
      max_sub = 0.0;
      for (int i = 1; i <= hist_sub->GetXaxis()->GetNbins(); i++) {
        for (int j = 1; j <= hist_sub->GetYaxis()->GetNbins(); j++) {
          if (hist_sub->GetBinContent(i, j) > max_sub) {
            max_sub = hist_sub->GetBinContent(i, j);
          }
        }
      }
      max_x = hist_sub->GetMean(1);
      max_y = hist_sub->GetMean(2);

      for (int i = npar1; i < npar; i++) {
        if (mdef->get_indiv_max_E() == i - npar1) {
          pval[i] = max_sub;
          perr[i] = mdef->chisquare_error(pval[i])*0.5;
          plo[i] = 0.0;
          phi[i] = 1.0e6;
        }
        else if (mdef->get_indiv_max_x() == i - npar1) {
          pval[i] = max_x;
          perr[i] = (energy.Xhi - energy.Xlo) / static_cast<double>(hist->GetXaxis()->GetNbins());
          plo[i] = 0.0;
          phi[i] = 0.0;
        }
        else if (mdef->get_indiv_max_y() == i - npar1) {
          pval[i] = max_y;
          perr[i] = (energy.Yhi - energy.Ylo) / static_cast<double>(hist->GetYaxis()->GetNbins());
          plo[i] = 0.0;
          phi[i] = 0.0;
        }
        else {
          string dummy;
          mdef->get_indiv_par(i-npar1, dummy, pval[i], perr[i], plo[i], phi[i]);
        }
      }
    }
    int n_pars_to_set = init_spec_pars ? ngauss*mdef->get_formula()->GetNpar()
      : npar - npar1;
    int init_par_to_set = init_spec_pars ? 0 : npar1;
    for (int i = 0; i < n_pars_to_set; i++) {
      double dummy;
      string s;
      int ipar = i + init_par_to_set;
      mdef->get_indiv_par(i % mdef->get_formula()->GetNpar(), s,
                         dummy, dummy, dummy, dummy);
      ostringstream par_oss;
      par_oss << s << ipar / (mdef->get_formula()->GetNpar()) << flush;
      try {
        pars.at(ipar) = TString(par_oss.str());
      }
      catch (exception ex) {
        cerr << "exception 2 in par_init" << endl;
      }
      int error_flag;
      try {
        gMinuit->mnparm(ipar, pars.at(ipar),
                        pval[ipar], perr[ipar], plo[ipar], phi[ipar], error_flag);
      } catch (exception ex) {
        cerr << "exception 3 in par_init" << endl;
      }
    }
  }

  results fit_histo(TH2 *hist, vector<trouble> &t_vec,
                 void (*cc_minuit)(TMinuit *, TH2 *, int),
                 int start_ngauss,
                    int rebinX, int rebinY,
                    double P_cutoff_val) {
    TMinuit *gMinuit = new TMinuit();
    int npar_indiv = mdef->get_formula()->GetNpar();
    int istat, erflg;
    results r;

    gMinuit->SetFCN(fcn);
    gMinuit->mninit(5, 6, 7);

    // set error def and machine accuracy
    double cs_err_def = 1.0;
    double fcn_eps = 0.2;
    gMinuit->mnexcm("SET ERR", &cs_err_def, 1, erflg);
    gMinuit->mnexcm("SET EPS", &fcn_eps, 1, erflg);

    // rebin histogram
    TH2 *hist_rebinned;
    if (rebinX > 1 && rebinY > 1)
      hist_rebinned = hist->Rebin2D(rebinX, rebinY);
    else
      hist_rebinned = hist;

    r.hist_rebinned = hist_rebinned;
    // load histogram into energies vector
    energy.bins.resize(hist_rebinned->GetXaxis()->GetNbins());
    for (int i = 0; i < energy.bins.size(); i++) {
      energy.bins[i].resize(hist_rebinned->GetYaxis()->GetNbins());
      for (int j = 0; j < energy.bins[i].size(); j++) {
        energy.bins[i][j] = hist_rebinned->GetBinContent(i+1, j+1);
      }
    }

    energy.Xlo = hist->GetXaxis()->GetXmin();
    energy.Xhi = hist->GetXaxis()->GetXmax();
    energy.Ylo = hist->GetYaxis()->GetXmin();
    energy.Yhi = hist->GetYaxis()->GetXmax();
    
    if (start_ngauss < 1) {
      start_ngauss = 1;
    }

    for (ngauss = start_ngauss;
         ngauss <= (MAX_GAUSS > start_ngauss ? MAX_GAUSS : start_ngauss);
         ngauss++) {
      t_vec.resize(t_vec.size() + 1);
      int npar = npar_indiv*ngauss;
      double pval[256], perr[256], plo[256], phi[256];
      if (npar > 256) {
        cerr << "Parameter overload" << endl;
        return r;
      }
      vector<TString> pars(npar);

      // initialize parameters
      par_init(hist, gMinuit, pars, pval, perr, plo, phi, npar, r);

      // minimize
      double chisquare, edm, errdef;
      int nvpar, nparx;
      trouble t;
      t.occ = T_NULL;
      t.istat = 3;
      // fix sigmas of the Gaussians
      for (int i = 0; i < ngauss; i++) {
        double parno[2];
        parno[0] = i*npar_indiv + 4;
        gMinuit->mnexcm("FIX", parno, 1, erflg);
      }
      gMinuit->mnexcm("SIMPLEX", 0, 0, erflg);
      gMinuit->mnexcm("MIGRAD", 0, 0, erflg);
      gMinuit->mnstat(chisquare, edm, errdef, nvpar, nparx, istat);
      if (istat == 3) {
        /* we're not concerned about MINOS errors right now
        gMinuit->mnexcm("MINOS", 0, 0, erflg);
        gMinuit->mnstat(chisquare, edm, errdef, nvpar, nparx, istat);
        if (istat != 3) {
          t.occ = T_MINOS;
          t.istat = istat;
        }
        */
      }
      else {
        t.occ = T_MIGRAD;
        t.istat = istat;
      }

      try {
        if (t_vec.size() < ngauss) {
          t_vec.resize(ngauss);
        }
        t_vec.at(ngauss-1) = t;
      }
      catch (exception ex) {
        cerr << "exception in fit_histo" << endl;
      }

      // put parameters in map
      for (int i = 0; i < npar && i < 256; i++) {
        int iuint; // internal parameter number
        gMinuit->mnpout(i, pars[i], pval[i], perr[i], plo[i], phi[i], iuint);
      }
      vector<double> pval_copy(npar);
      vector<double> perr_copy(npar);
      vector<double> plo_copy(npar);
      vector<double> phi_copy(npar);
      for (int i = 0; i < npar && i < 256; i++) {
        pval_copy[i] = pval[i];
        perr_copy[i] = perr[i];
        plo_copy[i] = plo[i];
        phi_copy[i] = phi[i];
      }
      r.pars.push_back(pars);
      r.pval.push_back(pval_copy);
      r.perr.push_back(perr_copy);
      r.plo.push_back(plo_copy);
      r.phi.push_back(phi_copy);

      // execute user minuit code
      if (cc_minuit != 0)
        (*cc_minuit)(gMinuit, hist_rebinned, ngauss);

      int ndof = 0;
      if (!ignorezero)
        ndof = energy.bins.size() * energy.bins[0].size();
      else {
        for (int i = 0; i < energy.bins.size(); i++) {
          for (int j = 0; j < energy.bins[i].size(); j++) {
            if (energy.bins[i][j] > 1.0e-30)
              ndof++;
          }
        }
      }
      ndof -= npar;

      r.chisquare.push_back(chisquare);
      double P = prob(chisquare, ndof);
      if (P > P_cutoff_val) {
        break;
      }
    }

    delete gMinuit;
    return r;
  }
}
Revision:	1.8
Committed:	Tue Nov 10 04:37:51 2009 UTC (15 years, 5 months ago) by dnisson
Branch:	MAIN
CVS Tags:	V00-01-02
Changes since 1.7:	+8 -7 lines
Log Message:	Fixed negative N values
#	Content
1	/* jetfit.cpp - Package to fit multi-Gaussian distributions to histograms
2	* rewrite after accidental deletion 07-24-09
3	* Author: David Nisson
4	*/
5
6	#include <cstdlib>
7	#include <cmath>
8	#include <ctime>
9	#include <cstdio>
10	#include <cstring>
11	#include <cctype>
12	#include <iostream>
13	#include <fstream>
14	#include <sstream>
15	#include <string>
16	#include <vector>
17	#include <set>
18	#include <map>
19	#include <limits>
20	#include <exception>
21
22	#include <TMinuit.h>
23	#include <TH1.h>
24	#include <TH2.h>
25	#include <TF2.h>
26	#include <TRandom3.h>
27	#include <Rtypes.h>
28	#include <TFormula.h>
29	#include <TSystem.h>
30
31	#include "UserCode/JetFitAnalyzer/interface/jetfit.h"
32
33	#define PI 3.141592653
34
35	#define MAX_GAUSS 3
36
37	using namespace std;
38
39	namespace jetfit {
40	// configurable options
41	bool ignorezero = false; // ignore zero bins when fitting
42
43	int ngauss; // number of Gaussians in current model
44
45	struct histo {
46	vector< vector<double> > bins;
47	double Xlo, Xhi, Ylo, Yhi;
48	} energy;
49
50
51	model_def *mdef;
52
53	model_def& curr_model_def() {
54	return *mdef;
55	}
56
57	void set_model_def(model_def *_mdef) {
58	mdef = _mdef;
59	}
60
61	int get_ngauss() {
62	return ngauss;
63	}
64
65	void set_ngauss(int _ngauss) {
66	ngauss = _ngauss;
67	}
68
69	// fit function
70	double fit_fcn(double x, double y, double *xval) {
71	int npar_indiv = mdef->get_formula()->GetNpar();
72	double val = 0.0;
73	for (int i = 0; i < ngauss; i++) {
74	mdef->get_formula()->SetParameters(xval + i*npar_indiv);
75	val += mdef->get_formula()->Eval(x, y);
76	}
77	return val;
78	}
79
80	// TF2-compatible fit function
81	double fit_fcn_TF2(double x, double pval) {
82	double val = fit_fcn(x[0], x[1], pval);
83	return val;
84	}
85
86	// Integral of model formula / chisquare sigma
87	double formula_int(double xlo, double xhi, double ylo, double yhi,
88	double *pval, double XbinSize, double YbinSize,
89	double *xval) {
90	double xstep = (xhi - xlo) / static_cast<double>(20);
91	double ystep = (yhi - ylo) / static_cast<double>(20);
92
93	double fsum = 0.0;
94	double pval_old[256];
95	int npar = mdef->get_formula()->GetNpar();
96	if (npar > 256) {
97	cerr << "Parameter overload" << endl;
98	return 0.0;
99	}
100	mdef->get_formula()->GetParameters(pval_old);
101	mdef->get_formula()->SetParameters(pval);
102
103	for (int i = 0; i < 20; i++) {
104	for (int j = 0; j < 20; j++) {
105	double x = (static_cast<double>(i) + 0.5)*xstep + xlo;
106	double y = (static_cast<double>(j) + 0.5)*ystep + ylo;
107	double sig_cut = 1.0e-5;
108	double nu = XbinSize * YbinSize * fit_fcn(x, y, xval);
109	double sigma = fabs(mdef->chisquare_error(0.0)) < sig_cut
110	? sig_cut : mdef->chisquare_error(0.0);
111
112	fsum += pow(xstep * ystep * mdef->get_formula()->Eval(x, y), 2.0)
113	/ sigma / sigma;
114	}
115	}
116
117	mdef->get_formula()->SetParameters(pval_old);
118	return fsum;
119	}
120
121	// MINUIT objective function
122	void fcn(int &npar, double grad, double &fcnval, double xval, int iflag)
123	{
124	double chisquare = 0.0;
125	double XbinSize = (energy.Xhi - energy.Xlo)
126	/ static_cast<double>(energy.bins.size());
127	double YbinSize = (energy.Yhi - energy.Ylo)
128	/ static_cast<double>(energy.bins.at(0).size());
129	try {
130	// add errors in data points in histogram
131	for (int i = 0; i < energy.bins.size(); i++) {
132	for (int j = 0; j < energy.bins.at(i).size(); j++) {
133	double x = (static_cast<double>(i) + 0.5) * (energy.Xhi - energy.Xlo)
134	/ static_cast<double>(energy.bins.size()) + energy.Xlo;
135	double y = (static_cast<double>(j) + 0.5) * (energy.Yhi - energy.Ylo)
136	/ static_cast<double>(energy.bins.at(i).size()) + energy.Ylo;
137	double nu = fit_fcn(x, y, xval) * XbinSize * YbinSize;
138	double sig_cut = 1.0e-5;
139	if (fabs(mdef->chisquare_error(energy.bins.at(i).at(j))) > sig_cut \|\| !ignorezero) {
140	chisquare += pow(energy.bins.at(i).at(j) - nu, 2.0)
141	/ pow(mdef->chisquare_error(energy.bins.at(i).at(j)), 2.0);
142	}
143	else {
144	chisquare += pow(energy.bins.at(i).at(j) - nu, 2.0)
145	/ pow(sig_cut, 2.0);
146	}
147	}
148	}
149
150	// add errors due to Gaussians outside histogram
151	double eps = 0.01; // accuracy set for this function
152	for (int i = 0; i < ngauss; i++) {
153	double pval = xval+i(mdef->get_formula()->GetNpar());
154	double par_x = pval[mdef->get_indiv_max_x()];
155	double par_y = pval[mdef->get_indiv_max_y()];
156	double par_sig = pval[3];
157	double cutoff_rad = sqrt(-log(eps * 2.0 * PI * par_sig * par_sig
158	/ pval[0]) * 2.0 * par_sig * par_sig);
159
160	bool left = par_x < energy.Xlo + cutoff_rad;
161	bool right = par_x > energy.Xhi - cutoff_rad;
162	bool top = par_y > energy.Yhi - cutoff_rad;
163	bool bottom = par_y < energy.Ylo + cutoff_rad;
164
165	if (left) {
166	double xlo = par_x - cutoff_rad;
167	double xhi = energy.Xlo;
168	double ylo = energy.Ylo;
169	double yhi = energy.Yhi;
170	chisquare += 2.0*formula_int(xlo, xhi, ylo, yhi, pval,
171	XbinSize, YbinSize, xval);
172	}
173	if (right) {
174	double xlo = energy.Xhi;
175	double xhi = par_x + cutoff_rad;
176	double ylo = energy.Ylo;
177	double yhi = energy.Yhi;
178	chisquare += 2.0*formula_int(xlo, xhi, ylo, yhi, pval,
179	XbinSize, YbinSize, xval);
180	}
181	if (top) {
182	double xlo = left ? par_x - cutoff_rad : energy.Xlo;
183	double xhi = right ? par_x + cutoff_rad : energy.Xhi;
184	double ylo = energy.Yhi;
185	double yhi = par_y + cutoff_rad;
186	chisquare += 2.0*formula_int(xlo, xhi, ylo, yhi, pval,
187	XbinSize, YbinSize, xval);
188	}
189	if (bottom) {
190	double xlo = left ? par_x - cutoff_rad : energy.Xlo;
191	double xhi = right ? par_x + cutoff_rad : energy.Xhi;
192	double ylo = par_y - cutoff_rad;
193	double yhi = energy.Ylo;
194	chisquare += 2.0*formula_int(xlo, xhi, ylo, yhi, pval,
195	XbinSize, YbinSize, xval);
196	}
197	}
198
199	fcnval = chisquare;
200	}
201	catch (exception ex) {
202	cerr << "Exception in jetfit::fcn" << endl;
203	}
204	}
205
206	bool get_ignorezero() {
207	return ignorezero;
208	}
209
210	void set_ignorezero(bool _iz) {
211	ignorezero = _iz;
212	}
213
214	TFormula * model_def::get_formula() {
215	return indiv_formula;
216	}
217
218	void model_def::set_formula(TFormula *new_formula) {
219	indiv_formula = new_formula;
220	}
221
222	void model_def::get_indiv_par(int i, string &name, double &start, double &step,
223	double &lo, double &hi) {
224	try {
225	name = indiv_par_names.at(i);
226	start = indiv_par_starts.at(i);
227	step = indiv_par_start_steps.at(i);
228	lo = indiv_par_lo.at(i);
229	hi = indiv_par_hi.at(i);
230	} catch (exception ex) {
231	cerr << "exception in jetfit::model_def::get_indiv_par" << endl;
232	}
233	}
234
235	void model_def::set_indiv_par(int i, string name, double start, double step,
236	double lo, double hi) {
237	if (indiv_par_names.size() < i+1) {
238	indiv_par_names.resize(i+1);
239	indiv_par_starts.resize(i+1);
240	indiv_par_start_steps.resize(i+1);
241	indiv_par_lo.resize(i+1);
242	indiv_par_hi.resize(i+1);
243	}
244	try {
245	indiv_par_names.at(i) = name;
246	indiv_par_starts.at(i) = start;
247	indiv_par_start_steps.at(i) = step;
248	indiv_par_lo.at(i) = lo;
249	indiv_par_hi.at(i) = hi;
250	}
251	catch (exception ex) {
252	cerr << "exception in jetfit::model_def::set_indiv_par" << endl;
253	}
254	}
255
256	int model_def::get_indiv_max_E() {
257	return indiv_max_E;
258	}
259
260	void model_def::set_indiv_max_E(int _new_max_E) {
261	indiv_max_E = _new_max_E;
262	}
263
264	int model_def::get_indiv_max_x() {
265	return indiv_max_x;
266	}
267
268	void model_def::set_indiv_max_x(int new_max_x) {
269	indiv_max_x = new_max_x;
270	}
271
272	int model_def::get_indiv_max_y() {
273	return indiv_max_y;
274	}
275
276	void model_def::set_indiv_max_y(int new_max_y) {
277	indiv_max_y = new_max_y;
278	}
279
280	unsigned model_def::get_n_special_par_sets() {
281	return special_par_starts.size();
282	}
283
284	void model_def::get_special_par(int g, int i, double &pstart,
285	double &perr, double &plo, double &phi) {
286	try {
287	pstart = special_par_starts.at(g).at(i);
288	perr = special_par_start_steps.at(g).at(i);
289	plo = special_par_lo.at(g).at(i);
290	phi = special_par_hi.at(g).at(i);
291	} catch (exception ex) {
292	cerr << "Exception in model_def::get_special_par" << endl;
293	}
294	}
295
296	void model_def::set_special_par(int g, int i, double pstart,
297	double perr, double plo, double phi) {
298	if (g+1 > special_par_starts.size()) {
299	special_par_starts.resize(g+1);
300	special_par_start_steps.resize(g+1);
301	special_par_lo.resize(g+1);
302	special_par_hi.resize(g+1);
303	}
304
305	try {
306	if (i+1 > special_par_starts.at(g).size()) {
307	special_par_starts.at(g).resize(i+1);
308	special_par_start_steps.at(g).resize(i+1);
309	special_par_lo.at(g).resize(i+1);
310	special_par_hi.at(g).resize(i+1);
311	}
312
313	special_par_starts.at(g).at(i) = pstart;
314	special_par_start_steps.at(g).at(i) = perr;
315	special_par_lo.at(g).at(i) = plo;
316	special_par_hi.at(g).at(i) = phi;
317	}
318	catch (exception ex) {
319	cerr << "exception in jetfit::model_def::set_special_par" << endl;
320	}
321	}
322
323	// translation of CERN's ERFC function
324	double erfc(double x) {
325	bool lef = false;
326	double p2[5], q2[5];
327
328	const double z1 = 1.0, hf = z1/2.0, c1 = 0.56418958;
329	const double vmax = 7.0;
330	const double switch_ = 4.0;
331
332	double p10 = 3.6767877, q10 = 3.2584593, p11 = -9.7970465e-2;
333	p2[0] = 7.3738883;
334	q2[0] = 7.3739609;
335	p2[1] = 6.8650185;
336	q2[1] = 1.5184908e1;
337	p2[2] = 3.0317993;
338	q2[2] = 1.2795530e1;
339	p2[3] = 5.6316962e-1;
340	q2[3] = 5.3542168;
341	p2[4] = 4.3187787e-5;
342	q2[4] = 1.0;
343
344	double p30 = -1.2436854e-1, q30 = 4.4091706e-1, p31 = -9.6821036e-2;
345
346	double v = fabs(x);
347	double y, h, hc, ap, aq;
348	if (v < hf) {
349	y = v*v;
350	h = x(p10 + p11y)/(q10 + y);
351	hc = 1.0 - h;
352	}
353	else {
354	if (v < switch_) {
355	ap = p2[4];
356	aq = q2[4];
357	for (int i = 3; i >= 0; i--) {
358	ap = p2[i] + v*ap;
359	aq = q2[i] + v*aq;
360	}
361	hc = exp(-vv)ap/aq;
362	h = 1.0 - hc;
363	}
364	else if (v < vmax) {
365	y = 1/v/v;
366	hc = exp(-vv)(c1 + y(p30 + p31y)/(q30 + y))/v;
367	h = 1.0 - hc;
368	}
369	// for very big values we can save us any calculation
370	// and the FP-exceptions from exp
371	else {
372	h = 1.0;
373	hc = 0.0;
374	}
375	if (x < 0) {
376	h = -h;
377	hc = 2.0 - hc;
378	}
379	}
380	if (lef) {
381	return h;
382	}
383	else {
384	return hc;
385	}
386	}
387
388	// translation of CERN's PROB function
389	double prob(double x, int n) {
390	const char *name = "PROB";
391	char errtxt[80];
392
393	const double r1 = 1.0,
394	hf = r1/2.0, th = r1/3.0, f1 = 2.0*r1/9.0;
395	const double c1 = 1.128379167095513;
396	const int nmax = 300;
397	// maximum chi2 per df for df >= 2., if chi2/df > chipdf prob=0
398	const double chipdf = 100.0;
399	const double xmax = 174.673, xmax2 = 2.0*xmax;
400	const double xlim = 24.0;
401	const double eps = 1e-30;
402
403	double y = x;
404	double u = hf*y;
405	double h, w, s, t, fi, e;
406	int m;
407	if (n < 0) {
408	h = 0.0;
409	sprintf(errtxt, "n = %d < 1", n);
410	cerr << "PROB: G100.1: "<<errtxt;
411	}
412	else if (y < 0.0) {
413	h = 0.0;
414	sprintf(errtxt, "x = %f < 0", n);
415	cerr << "PROB: G100.2: "<<errtxt;
416	}
417	else if (y == 0.0 \|\| n/20 > y) {
418	h = 1.0;
419	}
420	else if (n == 1) {
421	w = sqrt(u);
422	if (w < xlim) {
423	h = erfc(w);
424	}
425	else {
426	h = 0.0;
427	}
428	}
429	else if (n > nmax) {
430	s = r1 / ((double)n);
431	t = f1 * s;
432	w = (pow(ys, th) - (1.0 - t)) / sqrt(2.0t);
433	if (w < -xlim) {
434	h = 1.0;
435	}
436	else if (w < xlim) {
437	h = hf * erfc(w);
438	}
439	else {
440	h = 0.0;
441	}
442	}
443	else {
444	m = n/2;
445	if (u < xmax2 && (y/n) <= chipdf) {
446	s = exp(-hf*u);
447	t = s;
448	e = s;
449	if (2*m == n) {
450	fi = 0.0;
451	for (int i = 1; i < m; i++) {
452	fi += 1.0;
453	t = u*t/fi;
454	s += t;
455	}
456	h = s*e;
457	}
458	else {
459	fi = 1.0;
460	for (int i = 1; i < m; i++) {
461	fi += 2.0;
462	t = t*y/fi;
463	s += t;
464	}
465	w = sqrt(u);
466	if (w < xlim) {
467	h = c1ws*e + erfc(w);
468	}
469	else {
470	h = 0.0;
471	}
472	}
473	}
474	else {
475	h = 0.0;
476	}
477	}
478	if (h > eps) {
479	return h;
480	}
481	else {
482	return 0.0;
483	}
484	}
485
486	void fill_histo_with_vec(TH2 *hist, vector< vector<double> > &vec) {
487	for (int i = 0; i < vec.size(); i++) {
488	for (int j = 0; j < vec[i].size(); j++) {
489	hist->SetBinContent(i+1, j+1, vec[i][j]);
490	}
491	}
492	}
493
494	void par_init(TH2 hist, TMinuit gMinuit, vector<TString> &pars,
495	double pval, double perr, double plo, double phi,
496	int npar, results r) {
497	int npar1 = npar - mdef->get_formula()->GetNpar();
498	bool init_spec_pars = false;
499	if (ngauss <= mdef->get_n_special_par_sets()) {
500	init_spec_pars = true;
501	for (int k = 0; k < ngauss; k++) {
502	int ipar0 = k*mdef->get_formula()->GetNpar(); // index of indiv par 0
503	for (int l = 0; l < mdef->get_formula()->GetNpar(); l++) {
504	int ipar = ipar0 + l;
505	if (ipar < npar)
506	mdef->get_special_par(k, l, pval[ipar], perr[ipar], plo[ipar],
507	phi[ipar]);
508	else
509	cerr << "WARNING: Attempt to set parameter out of index range!"
510	<< endl;
511	}
512	}
513	}
514	else {
515	double XbinSize = (energy.Xhi - energy.Xlo)
516	/ static_cast<double>(energy.bins.size());
517	double YbinSize = (energy.Xhi - energy.Xlo)
518	/ static_cast<double>(energy.bins.at(0).size());
519	vector< vector<double> > sub_energy(energy.bins.size());
520	double max_sub, max_x = 0.0, max_y = 0.0;
521	double pval_other[256];
522	max_sub = -(numeric_limits<double>::max());
523	for (int i = 0; i < energy.bins.size(); i++) {
524	sub_energy[i].resize(energy.bins[i].size());
525	for (int j = 0; j < energy.bins[i].size(); j++) {
526	double x = static_cast<double>(i)*(energy.Xhi - energy.Xlo)
527	/ static_cast<double>(energy.bins.size()) + energy.Xlo;
528	double y = static_cast<double>(j)*(energy.Yhi - energy.Ylo)
529	/ static_cast<double>(energy.bins[i].size()) + energy.Ylo;
530	if (ngauss > 1) {
531	// subtract integral of fit function
532	try {
533	int npval_other = r.pval.at(r.pval.size()-1).size();
534	if (npval_other > 256) {
535	cerr << "Parameter overload" << endl;
536	return;
537	}
538	for (int k = 0; k < npval_other; k++) {
539	pval_other[k] = r.pval[r.pval.size()-1][k];
540	}
541	ngauss--;
542	double nu = fit_fcn(x, y, pval_other) * XbinSize * YbinSize;
543	ngauss++;
544	sub_energy[i][j] = energy.bins[i][j] - nu;
545	}
546	catch (exception ex) {
547	cerr << "Exception in par_init" << endl;
548	}
549	}
550	else {
551	sub_energy[i][j] = energy.bins[i][j];
552	}
553	}
554	}
555	TH2D *hist_sub = new TH2D("hist_sub", "Subtracted histo",
556	sub_energy.size(), energy.Xlo,
557	energy.Xhi,
558	sub_energy[0].size(), energy.Ylo,
559	energy.Yhi);
560	fill_histo_with_vec(hist_sub, sub_energy);
561	max_sub = 0.0;
562	for (int i = 1; i <= hist_sub->GetXaxis()->GetNbins(); i++) {
563	for (int j = 1; j <= hist_sub->GetYaxis()->GetNbins(); j++) {
564	if (hist_sub->GetBinContent(i, j) > max_sub) {
565	max_sub = hist_sub->GetBinContent(i, j);
566	}
567	}
568	}
569	max_x = hist_sub->GetMean(1);
570	max_y = hist_sub->GetMean(2);
571
572	for (int i = npar1; i < npar; i++) {
573	if (mdef->get_indiv_max_E() == i - npar1) {
574	pval[i] = max_sub;
575	perr[i] = mdef->chisquare_error(pval[i])*0.5;
576	plo[i] = 0.0;
577	phi[i] = 1.0e6;
578	}
579	else if (mdef->get_indiv_max_x() == i - npar1) {
580	pval[i] = max_x;
581	perr[i] = (energy.Xhi - energy.Xlo) / static_cast<double>(hist->GetXaxis()->GetNbins());
582	plo[i] = 0.0;
583	phi[i] = 0.0;
584	}
585	else if (mdef->get_indiv_max_y() == i - npar1) {
586	pval[i] = max_y;
587	perr[i] = (energy.Yhi - energy.Ylo) / static_cast<double>(hist->GetYaxis()->GetNbins());
588	plo[i] = 0.0;
589	phi[i] = 0.0;
590	}
591	else {
592	string dummy;
593	mdef->get_indiv_par(i-npar1, dummy, pval[i], perr[i], plo[i], phi[i]);
594	}
595	}
596	}
597	int n_pars_to_set = init_spec_pars ? ngauss*mdef->get_formula()->GetNpar()
598	: npar - npar1;
599	int init_par_to_set = init_spec_pars ? 0 : npar1;
600	for (int i = 0; i < n_pars_to_set; i++) {
601	double dummy;
602	string s;
603	int ipar = i + init_par_to_set;
604	mdef->get_indiv_par(i % mdef->get_formula()->GetNpar(), s,
605	dummy, dummy, dummy, dummy);
606	ostringstream par_oss;
607	par_oss << s << ipar / (mdef->get_formula()->GetNpar()) << flush;
608	try {
609	pars.at(ipar) = TString(par_oss.str());
610	}
611	catch (exception ex) {
612	cerr << "exception 2 in par_init" << endl;
613	}
614	int error_flag;
615	try {
616	gMinuit->mnparm(ipar, pars.at(ipar),
617	pval[ipar], perr[ipar], plo[ipar], phi[ipar], error_flag);
618	} catch (exception ex) {
619	cerr << "exception 3 in par_init" << endl;
620	}
621	}
622	}
623
624	results fit_histo(TH2 *hist, vector<trouble> &t_vec,
625	void (cc_minuit)(TMinuit , TH2 *, int),
626	int start_ngauss,
627	int rebinX, int rebinY,
628	double P_cutoff_val) {
629	TMinuit *gMinuit = new TMinuit();
630	int npar_indiv = mdef->get_formula()->GetNpar();
631	int istat, erflg;
632	results r;
633
634	gMinuit->SetFCN(fcn);
635	gMinuit->mninit(5, 6, 7);
636
637	// set error def and machine accuracy
638	double cs_err_def = 1.0;
639	double fcn_eps = 0.2;
640	gMinuit->mnexcm("SET ERR", &cs_err_def, 1, erflg);
641	gMinuit->mnexcm("SET EPS", &fcn_eps, 1, erflg);
642
643	// rebin histogram
644	TH2 *hist_rebinned;
645	if (rebinX > 1 && rebinY > 1)
646	hist_rebinned = hist->Rebin2D(rebinX, rebinY);
647	else
648	hist_rebinned = hist;
649
650	r.hist_rebinned = hist_rebinned;
651	// load histogram into energies vector
652	energy.bins.resize(hist_rebinned->GetXaxis()->GetNbins());
653	for (int i = 0; i < energy.bins.size(); i++) {
654	energy.bins[i].resize(hist_rebinned->GetYaxis()->GetNbins());
655	for (int j = 0; j < energy.bins[i].size(); j++) {
656	energy.bins[i][j] = hist_rebinned->GetBinContent(i+1, j+1);
657	}
658	}
659
660	energy.Xlo = hist->GetXaxis()->GetXmin();
661	energy.Xhi = hist->GetXaxis()->GetXmax();
662	energy.Ylo = hist->GetYaxis()->GetXmin();
663	energy.Yhi = hist->GetYaxis()->GetXmax();
664
665	if (start_ngauss < 1) {
666	start_ngauss = 1;
667	}
668
669	for (ngauss = start_ngauss;
670	ngauss <= (MAX_GAUSS > start_ngauss ? MAX_GAUSS : start_ngauss);
671	ngauss++) {
672	t_vec.resize(t_vec.size() + 1);
673	int npar = npar_indiv*ngauss;
674	double pval[256], perr[256], plo[256], phi[256];
675	if (npar > 256) {
676	cerr << "Parameter overload" << endl;
677	return r;
678	}
679	vector<TString> pars(npar);
680
681	// initialize parameters
682	par_init(hist, gMinuit, pars, pval, perr, plo, phi, npar, r);
683
684	// minimize
685	double chisquare, edm, errdef;
686	int nvpar, nparx;
687	trouble t;
688	t.occ = T_NULL;
689	t.istat = 3;
690	// fix sigmas of the Gaussians
691	for (int i = 0; i < ngauss; i++) {
692	double parno[2];
693	parno[0] = i*npar_indiv + 4;
694	gMinuit->mnexcm("FIX", parno, 1, erflg);
695	}
696	gMinuit->mnexcm("SIMPLEX", 0, 0, erflg);
697	gMinuit->mnexcm("MIGRAD", 0, 0, erflg);
698	gMinuit->mnstat(chisquare, edm, errdef, nvpar, nparx, istat);
699	if (istat == 3) {
700	/* we're not concerned about MINOS errors right now
701	gMinuit->mnexcm("MINOS", 0, 0, erflg);
702	gMinuit->mnstat(chisquare, edm, errdef, nvpar, nparx, istat);
703	if (istat != 3) {
704	t.occ = T_MINOS;
705	t.istat = istat;
706	}
707	*/
708	}
709	else {
710	t.occ = T_MIGRAD;
711	t.istat = istat;
712	}
713
714	try {
715	if (t_vec.size() < ngauss) {
716	t_vec.resize(ngauss);
717	}
718	t_vec.at(ngauss-1) = t;
719	}
720	catch (exception ex) {
721	cerr << "exception in fit_histo" << endl;
722	}
723
724	// put parameters in map
725	for (int i = 0; i < npar && i < 256; i++) {
726	int iuint; // internal parameter number
727	gMinuit->mnpout(i, pars[i], pval[i], perr[i], plo[i], phi[i], iuint);
728	}
729	vector<double> pval_copy(npar);
730	vector<double> perr_copy(npar);
731	vector<double> plo_copy(npar);
732	vector<double> phi_copy(npar);
733	for (int i = 0; i < npar && i < 256; i++) {
734	pval_copy[i] = pval[i];
735	perr_copy[i] = perr[i];
736	plo_copy[i] = plo[i];
737	phi_copy[i] = phi[i];
738	}
739	r.pars.push_back(pars);
740	r.pval.push_back(pval_copy);
741	r.perr.push_back(perr_copy);
742	r.plo.push_back(plo_copy);
743	r.phi.push_back(phi_copy);
744
745	// execute user minuit code
746	if (cc_minuit != 0)
747	(*cc_minuit)(gMinuit, hist_rebinned, ngauss);
748
749	int ndof = 0;
750	if (!ignorezero)
751	ndof = energy.bins.size() * energy.bins[0].size();
752	else {
753	for (int i = 0; i < energy.bins.size(); i++) {
754	for (int j = 0; j < energy.bins[i].size(); j++) {
755	if (energy.bins[i][j] > 1.0e-30)
756	ndof++;
757	}
758	}
759	}
760	ndof -= npar;
761
762	r.chisquare.push_back(chisquare);
763	double P = prob(chisquare, ndof);
764	if (P > P_cutoff_val) {
765	break;
766	}
767	}
768
769	delete gMinuit;
770	return r;
771	}
772	}