Rf 5 1 2_Wsfactory_Oper¶

'ORGANIZATION AND SIMULTANEOUS FITS' RooFit tutorial macro #512

Illustration of operator expressions and expression-based basic p.d.f.s in the workspace factory syntax

Author: Wouter Verkerke (C version)
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Monday, January 17, 2022 at 10:06 AM.

In [ ]:
import ROOT

w = ROOT.RooWorkspace("w")

You can define typedefs for even shorter construction semantics

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w.factory("$Typedef(Gaussian,Gaus)") w.factory("$Typedef(Chebychev,Cheby)")

Operator pdf examples¶

PDF addition is done with SUM (coef1*pdf1,pdf2)

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w.factory("SUM::summodel( f[0,1]*Gaussian::gx(x[-10,10],m,1.0), Chebychev::ch(x,{0.1,0.2,-0.3}) )")

Extended PDF addition is done with SUM (yield1pdf1,yield2pdf2)

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w.factory("SUM::extsummodel( Nsig[0,1000]*gx, Nbkg[0,1000]*ch )")

PDF multiplication is done with PROD ( pdf1, pdf2 )

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w.factory("PROD::gxz( gx, Gaussian::gz(z[-10,10],0,1) )")

Conditional p.d.f multiplication is done with PROD ( pdf1|obs, pdf2 )

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w.factory("Gaussian::gy( y[-10,10], x, 1.0 )")
w.factory("PROD::gxycond( gy|x, gx )")

Convolution (numeric/ fft) is done with NCONV/FCONV (obs,pdf1,pdf2)

In [ ]:
w.factory("FCONV::lxg( x, Gaussian::g(x,mg,1), Landau::lc(x,0,1) )")

Simultaneous p.d.f.s are constructed with SIMUL( index, state1=pdf1, state2=pdf2,...)

In [ ]:
w.factory("SIMUL::smodel( c[A=0,B=1], A=Gaussian::gs(x,m,s), B=Landau::ls(x,0,1) )")

Operator function examples¶

Function multiplication is done with prod (func1, func2,...)

In [ ]:
w.factory("prod::uv(u,v)")

Function addition is done with sum(func1,func2)

In [ ]:
w.factory("sum::uv2(u,v)")

Interpreted and compiled expression based pdfs¶

Create a ROOT.RooGenericPdf interpreted p.d.f. You can use single quotes to pass the expression string argument

In [ ]:
w.factory("EXPR::G('x*x+1',x)")

Create a custom compiled p.d.f similar to the above interpreted p.d.f. The code required to make self p.d.f. is automatically embedded in the workspace

In [ ]:
w.factory("CEXPR::GC('x*x+a',{x,a})")

Compiled and interpreted functions (rather than p.d.f.s) can be made with the lower case 'expr' and 'cexpr' types

Print workspace contents

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w.Print()

Make workspace visible on command line

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