rf105_funcbinding.C File Reference

Detailed Description

Basic functionality: binding ROOT math functions as RooFit functions and pdfs

 
 
␛[1mRooFit v3.60 -- Developed by Wouter Verkerke and David Kirkby␛[0m 
                Copyright (C) 2000-2013 NIKHEF, University of California & Stanford University
                All rights reserved, please read http://roofit.sourceforge.net/license.txt
 
RooCFunction1Binding<double,double>::erf[ function=TMath::Erf x=x ] = 0
RooCFunction3PdfBinding<double,double,double,double>::beta[ function=ROOT::Math::beta_pdf x=x2 a=a b=b ] = 0.934689
[#1] INFO:NumericIntegration -- RooRealIntegral::init(beta_Int[x2]) using numeric integrator RooIntegrator1D to calculate Int(x2)
[#1] INFO:NumericIntegration -- RooRealIntegral::init(beta_Int[x2]) using numeric integrator RooIntegrator1D to calculate Int(x2)
[#1] INFO:NumericIntegration -- RooRealIntegral::init(beta_Int[x2]) using numeric integrator RooIntegrator1D to calculate Int(x2)
[#1] INFO:Minization -- RooMinimizer::optimizeConst: activating const optimization
 **********
 **    1 **SET PRINT           1
 **********
 **********
 **    2 **SET NOGRAD
 **********
 PARAMETER DEFINITIONS:
    NO.   NAME         VALUE      STEP SIZE      LIMITS
     1 a            5.00000e+00  1.00000e+00    0.00000e+00  1.00000e+01
     2 b            2.00000e+00  1.00000e+00    0.00000e+00  1.00000e+01
 **********
 **    3 **SET ERR         0.5
 **********
 **********
 **    4 **SET PRINT           1
 **********
 **********
 **    5 **SET STR           1
 **********
 NOW USING STRATEGY  1: TRY TO BALANCE SPEED AGAINST RELIABILITY
 **********
 **    6 **MIGRAD        1000           1
 **********
 FIRST CALL TO USER FUNCTION AT NEW START POINT, WITH IFLAG=4.
 START MIGRAD MINIMIZATION.  STRATEGY  1.  CONVERGENCE WHEN EDM .LT. 1.00e-03
 FCN=-4851.7 FROM MIGRAD    STATUS=INITIATE       10 CALLS          11 TOTAL
                     EDM= unknown      STRATEGY= 1      NO ERROR MATRIX       
  EXT PARAMETER               CURRENT GUESS       STEP         FIRST   
  NO.   NAME      VALUE            ERROR          SIZE      DERIVATIVE 
   1  a            5.00000e+00   1.00000e+00   2.01358e-01  -5.86406e+01
   2  b            2.00000e+00   1.00000e+00   2.57889e-01   3.98974e+02
                               ERR DEF= 0.5
 MIGRAD MINIMIZATION HAS CONVERGED.
 MIGRAD WILL VERIFY CONVERGENCE AND ERROR MATRIX.
 COVARIANCE MATRIX CALCULATED SUCCESSFULLY
 FCN=-4851.9 FROM MIGRAD    STATUS=CONVERGED      39 CALLS          40 TOTAL
                     EDM=4.45664e-07    STRATEGY= 1      ERROR MATRIX ACCURATE 
  EXT PARAMETER                                   STEP         FIRST   
  NO.   NAME      VALUE            ERROR          SIZE      DERIVATIVE 
   1  a            4.99036e+00   7.12139e-02   3.69873e-04   8.65175e-02
   2  b            1.98812e+00   2.63908e-02   1.71677e-04  -1.47761e-01
                               ERR DEF= 0.5
 EXTERNAL ERROR MATRIX.    NDIM=  25    NPAR=  2    ERR DEF=0.5
  5.072e-03  1.582e-03 
  1.582e-03  6.965e-04 
 PARAMETER  CORRELATION COEFFICIENTS  
       NO.  GLOBAL      1      2
        1  0.84198   1.000  0.842
        2  0.84198   0.842  1.000
 **********
 **    7 **SET ERR         0.5
 **********
 **********
 **    8 **SET PRINT           1
 **********
 **********
 **    9 **HESSE        1000
 **********
 COVARIANCE MATRIX CALCULATED SUCCESSFULLY
 FCN=-4851.9 FROM HESSE     STATUS=OK             10 CALLS          50 TOTAL
                     EDM=4.46009e-07    STRATEGY= 1      ERROR MATRIX ACCURATE 
  EXT PARAMETER                                INTERNAL      INTERNAL  
  NO.   NAME      VALUE            ERROR       STEP SIZE       VALUE   
   1  a            4.99036e+00   7.12317e-02   7.39745e-05  -1.92762e-03
   2  b            1.98812e+00   2.63974e-02   3.43355e-05  -6.46475e-01
                               ERR DEF= 0.5
 EXTERNAL ERROR MATRIX.    NDIM=  25    NPAR=  2    ERR DEF=0.5
  5.074e-03  1.583e-03 
  1.583e-03  6.968e-04 
 PARAMETER  CORRELATION COEFFICIENTS  
       NO.  GLOBAL      1      2
        1  0.84207   1.000  0.842
        2  0.84207   0.842  1.000
[#1] INFO:Minization -- RooMinimizer::optimizeConst: deactivating const optimization
[#1] INFO:NumericIntegration -- RooRealIntegral::init(beta_Int[x2]) using numeric integrator RooIntegrator1D to calculate Int(x2)
RooTFnBinding::fa1[ TFn={fa1=sin(x)/x} obs=(x3) ] = -0.0547936

 
#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
#include "TMath.h"
#include "TF1.h"
#include "Math/DistFunc.h"
#include "RooTFnBinding.h"
 
using namespace RooFit;
 
void rf105_funcbinding()
{
 
   // B i n d   T M a t h : : E r f   C   f u n c t i o n
   // ---------------------------------------------------
 
   // Bind one-dimensional TMath::Erf function as RooAbsReal function
   RooRealVar x("x", "x", -3, 3);
   RooAbsReal *errorFunc = bindFunction("erf", TMath::Erf, x);
 
   // Print erf definition
   errorFunc->Print();
 
   // Plot erf on frame
   RooPlot *frame1 = x.frame(Title("TMath::Erf bound as RooFit function"));
   errorFunc->plotOn(frame1);
 
   // B i n d   R O O T : : M a t h : : b e t a _ p d f   C   f u n c t i o n
   // -----------------------------------------------------------------------
 
   // Bind pdf ROOT::Math::Beta with three variables as RooAbsPdf function
   RooRealVar x2("x2", "x2", 0, 0.999);
   RooRealVar a("a", "a", 5, 0, 10);
   RooRealVar b("b", "b", 2, 0, 10);
   RooAbsPdf *beta = bindPdf("beta", ROOT::Math::beta_pdf, x2, a, b);
 
   // Perf beta definition
   beta->Print();
 
   // Generate some events and fit
   RooDataSet *data = beta->generate(x2, 10000);
   beta->fitTo(*data);
 
   // Plot data and pdf on frame
   RooPlot *frame2 = x2.frame(Title("ROOT::Math::Beta bound as RooFit pdf"));
   data->plotOn(frame2);
   beta->plotOn(frame2);
 
   // B i n d   R O O T   T F 1   a s   R o o F i t   f u n c t i o n
   // ---------------------------------------------------------------
 
   // Create a ROOT TF1 function
   TF1 *fa1 = new TF1("fa1", "sin(x)/x", 0, 10);
 
   // Create an observable
   RooRealVar x3("x3", "x3", 0.01, 20);
 
   // Create binding of TF1 object to above observable
   RooAbsReal *rfa1 = bindFunction(fa1, x3);
 
   // Print rfa1 definition
   rfa1->Print();
 
   // Make plot frame in observable, plot TF1 binding function
   RooPlot *frame3 = x3.frame(Title("TF1 bound as RooFit function"));
   rfa1->plotOn(frame3);
 
   TCanvas *c = new TCanvas("rf105_funcbinding", "rf105_funcbinding", 1200, 400);
   c->Divide(3);
   c->cd(1);
   gPad->SetLeftMargin(0.15);
   frame1->GetYaxis()->SetTitleOffset(1.6);
   frame1->Draw();
   c->cd(2);
   gPad->SetLeftMargin(0.15);
   frame2->GetYaxis()->SetTitleOffset(1.6);
   frame2->Draw();
   c->cd(3);
   gPad->SetLeftMargin(0.15);
   frame3->GetYaxis()->SetTitleOffset(1.6);
   frame3->Draw();
}

Author

07/2008 - Wouter Verkerke

Definition in file rf105_funcbinding.C.