ROOT: tutorials/roofit/rf104_classfactory.C File Reference

ROOT 6.18/05
Reference Guide

Detailed Description

Basic functionality: The class factory for functions and p.d.f.s

NOTE: This demo uses code that is generated by the macro, therefore it cannot be compiled in one step by ACliC. To run this macro compiled with ACliC do

root>.x rf104_classfactory.C // run interpreted to generate code
root>.L MyPdfV3.cxx+         // Compile and load created class
root>.x rf104_classfactory.C+ // run compiled code

 
 
␛[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
 
(MyPdfV3) An instance of MyPdfV3.
[#1] INFO:Minization -- createNLL: caching constraint set under name CONSTR_OF_PDF_pdf_FOR_OBS_y with 0 entries
[#1] INFO:Minization -- RooMinimizer::optimizeConst: activating const optimization
 **********
 **    1 **SET PRINT           1
 **********
 **********
 **    2 **SET NOGRAD
 **********
 PARAMETER DEFINITIONS:
    NO.   NAME         VALUE      STEP SIZE      LIMITS
     1 b            2.00000e+00  2.00000e+00   -1.00000e+01  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         500           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=2568.49 FROM MIGRAD    STATUS=INITIATE        4 CALLS           5 TOTAL
                     EDM= unknown      STRATEGY= 1      NO ERROR MATRIX       
  EXT PARAMETER               CURRENT GUESS       STEP         FIRST   
  NO.   NAME      VALUE            ERROR          SIZE      DERIVATIVE 
   1  b            2.00000e+00   2.00000e+00   2.05758e-01   5.02230e+01
                               ERR DEF= 0.5
 MIGRAD MINIMIZATION HAS CONVERGED.
 MIGRAD WILL VERIFY CONVERGENCE AND ERROR MATRIX.
 COVARIANCE MATRIX CALCULATED SUCCESSFULLY
 FCN=2568.28 FROM MIGRAD    STATUS=CONVERGED      17 CALLS          18 TOTAL
                     EDM=9.63237e-09    STRATEGY= 1      ERROR MATRIX ACCURATE 
  EXT PARAMETER                                   STEP         FIRST   
  NO.   NAME      VALUE            ERROR          SIZE      DERIVATIVE 
   1  b            1.91995e+00   1.24398e-01   4.43576e-04   7.74259e-03
                               ERR DEF= 0.5
 EXTERNAL ERROR MATRIX.    NDIM=  25    NPAR=  1    ERR DEF=0.5
  1.548e-02 
 **********
 **    7 **SET ERR         0.5
 **********
 **********
 **    8 **SET PRINT           1
 **********
 **********
 **    9 **HESSE         500
 **********
 COVARIANCE MATRIX CALCULATED SUCCESSFULLY
 FCN=2568.28 FROM HESSE     STATUS=OK              5 CALLS          23 TOTAL
                     EDM=9.63457e-09    STRATEGY= 1      ERROR MATRIX ACCURATE 
  EXT PARAMETER                                INTERNAL      INTERNAL  
  NO.   NAME      VALUE            ERROR       STEP SIZE       VALUE   
   1  b            1.91995e+00   1.24398e-01   1.77431e-05   1.93194e-01
                               ERR DEF= 0.5
 EXTERNAL ERROR MATRIX.    NDIM=  25    NPAR=  1    ERR DEF=0.5
  1.548e-02 
[#1] INFO:Minization -- RooMinimizer::optimizeConst: deactivating const optimization
[#1] INFO:NumericIntegration -- RooRealIntegral::init(GenPdf_Int[x]) using numeric integrator RooIntegrator1D to calculate Int(x)
[#1] INFO:NumericIntegration -- RooRealIntegral::init(GenPdf_Int[x]) using numeric integrator RooIntegrator1D to calculate Int(x)
[#1] INFO:NumericIntegration -- RooRealIntegral::init(GenPdf_Int[x]) using numeric integrator RooIntegrator1D to calculate Int(x)
[#1] INFO:Minization -- RooMinimizer::optimizeConst: activating const optimization
 **********
 **   10 **SET PRINT           1
 **********
 **********
 **   11 **SET NOGRAD
 **********
 PARAMETER DEFINITIONS:
    NO.   NAME         VALUE      STEP SIZE      LIMITS
     1 alpha        5.00000e+00  9.90000e-01    1.00000e-01  1.00000e+01
 **********
 **   12 **SET ERR         0.5
 **********
 **********
 **   13 **SET PRINT           1
 **********
 **********
 **   14 **SET STR           1
 **********
 NOW USING STRATEGY  1: TRY TO BALANCE SPEED AGAINST RELIABILITY
 **********
 **   15 **MIGRAD         500           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=178267 FROM MIGRAD    STATUS=INITIATE        6 CALLS           7 TOTAL
                     EDM= unknown      STRATEGY= 1      NO ERROR MATRIX       
  EXT PARAMETER               CURRENT GUESS       STEP         FIRST   
  NO.   NAME      VALUE            ERROR          SIZE      DERIVATIVE 
   1  alpha        5.00000e+00   9.90000e-01   2.01369e-01   2.50886e+02
                               ERR DEF= 0.5
 MIGRAD MINIMIZATION HAS CONVERGED.
 MIGRAD WILL VERIFY CONVERGENCE AND ERROR MATRIX.
 COVARIANCE MATRIX CALCULATED SUCCESSFULLY
 FCN=178266 FROM MIGRAD    STATUS=CONVERGED      14 CALLS          15 TOTAL
                     EDM=3.47331e-06    STRATEGY= 1      ERROR MATRIX ACCURATE 
  EXT PARAMETER                                   STEP         FIRST   
  NO.   NAME      VALUE            ERROR          SIZE      DERIVATIVE 
   1  alpha        4.98248e+00   1.85558e-02   1.09523e-03  -4.97115e-01
                               ERR DEF= 0.5
 EXTERNAL ERROR MATRIX.    NDIM=  25    NPAR=  1    ERR DEF=0.5
  3.443e-04 
 **********
 **   16 **SET ERR         0.5
 **********
 **********
 **   17 **SET PRINT           1
 **********
 **********
 **   18 **HESSE         500
 **********
 COVARIANCE MATRIX CALCULATED SUCCESSFULLY
 FCN=178266 FROM HESSE     STATUS=OK              5 CALLS          20 TOTAL
                     EDM=3.46509e-06    STRATEGY= 1      ERROR MATRIX ACCURATE 
  EXT PARAMETER                                INTERNAL      INTERNAL  
  NO.   NAME      VALUE            ERROR       STEP SIZE       VALUE   
   1  alpha        4.98248e+00   1.85557e-02   2.19047e-04  -1.36416e-02
                               ERR DEF= 0.5
 EXTERNAL ERROR MATRIX.    NDIM=  25    NPAR=  1    ERR DEF=0.5
  3.443e-04 
[#1] INFO:Minization -- RooMinimizer::optimizeConst: deactivating const optimization
[#1] INFO:NumericIntegration -- RooRealIntegral::init(GenPdf_Int[x]) using numeric integrator RooIntegrator1D to calculate Int(x)

 
#include "RooRealVar.h"
#include "RooDataSet.h"
#include "RooGaussian.h"
#include "TCanvas.h"
#include "TAxis.h"
#include "RooPlot.h"
#include "RooClassFactory.h"
#include "TROOT.h"
 
using namespace RooFit;
 
void rf104_classfactory()
{
   // W r i t e   c l a s s   s k e l e t o n   c o d e
   // --------------------------------------------------
 
   // Write skeleton p.d.f class with variable x,a,b
   // To use this class,
   //    - Edit the file MyPdfV1.cxx and implement the evaluate() method in terms of x,a and b
   //    - Compile and link class with '.x MyPdfV1.cxx+'
   //
   RooClassFactory::makePdf("MyPdfV1", "x,A,B");
 
   // W i t h   a d d e d   i n i t i a l   v a l u e   e x p r e s s i o n
   // ---------------------------------------------------------------------
 
   // Write skeleton p.d.f class with variable x,a,b and given formula expression
   // To use this class,
   //    - Compile and link class with '.x MyPdfV2.cxx+'
   //
   RooClassFactory::makePdf("MyPdfV2", "x,A,B", "", "A*fabs(x)+pow(x-B,2)");
 
   // W i t h   a d d e d   a n a l y t i c a l   i n t e g r a l   e x p r e s s i o n
   // ---------------------------------------------------------------------------------
 
   // Write skeleton p.d.f class with variable x,a,b, given formula expression _and_
   // given expression for analytical integral over x
   // To use this class,
   //    - Compile and link class with '.x MyPdfV3.cxx+'
   //
   RooClassFactory::makePdf("MyPdfV3", "x,A,B", "", "A*fabs(x)+pow(x-B,2)", kTRUE, kFALSE,
                            "x:(A/2)*(pow(x.max(rangeName),2)+pow(x.min(rangeName),2))+(1./"
                            "3)*(pow(x.max(rangeName)-B,3)-pow(x.min(rangeName)-B,3))");
 
   // U s e   i n s t a n c e   o f   c r e a t e d   c l a s s
   // ---------------------------------------------------------
 
   // Compile MyPdfV3 class
   gROOT->ProcessLineSync(".x MyPdfV3.cxx+");
 
   // Create instance of MyPdfV3 class
   RooRealVar a("a", "a", 1);
   RooRealVar b("b", "b", 2, -10, 10);
   RooRealVar y("y", "y", -10, 10);
 
   // We need to hide the type to run in a ROOT macro
   RooWorkspace w("w");
   w.factory("MyPdfV3::pdf(y[-10,10], a[1], b[2,-10,10])");
   auto pdf = w.pdf("pdf");
 
   // Generate toy data from pdf and plot data and p.d.f on frame
   RooPlot *frame1 = y.frame(Title("Compiled class MyPdfV3"));
   RooDataSet *data = pdf->generate(y, 1000);
   pdf->fitTo(*data);
   data->plotOn(frame1);
   pdf->plotOn(frame1);
 
   // -----------------------------------------------------------------
   // C o m p i l e d   v e r s i o n   o f   e x a m p l e   r f 1 0 3
   // =================================================================
 
   // Declare observable x
   RooRealVar x("x", "x", -20, 20);
 
   // The RooClassFactory::makePdfInstance() function performs code writing, compiling, linking
   // and object instantiation in one go and can serve as a straight replacement of RooGenericPdf
 
   RooRealVar alpha("alpha", "alpha", 5, 0.1, 10);
   RooAbsPdf *genpdf =
      RooClassFactory::makePdfInstance("GenPdf", "(1+0.1*fabs(x)+sin(sqrt(fabs(x*alpha+0.1))))", RooArgSet(x, alpha));
 
   // Generate a toy dataset from the interpreted p.d.f
   RooDataSet *data2 = genpdf->generate(x, 50000);
 
   // Fit the interpreted p.d.f to the generated data
   genpdf->fitTo(*data2);
 
   // Make a plot of the data and the p.d.f overlaid
   RooPlot *frame2 = x.frame(Title("Compiled version of pdf of rf103"));
   data2->plotOn(frame2);
   genpdf->plotOn(frame2);
 
   // Draw all frames on a canvas
   TCanvas *c = new TCanvas("rf104_classfactory", "rf104_classfactory", 800, 400);
   c->Divide(2);
   c->cd(1);
   gPad->SetLeftMargin(0.15);
   frame1->GetYaxis()->SetTitleOffset(1.4);
   frame1->Draw();
   c->cd(2);
   gPad->SetLeftMargin(0.15);
   frame2->GetYaxis()->SetTitleOffset(1.4);
   frame2->Draw();
}

Author: 07/2008 - Wouter Verkerke

Definition in file rf104_classfactory.C.