Rf 5 0 9_Wsinteractive

Organization and simultaneous fits: easy interactive access to workspace contents - CINT to CLING code migration

Author: Clemens Lange, Wouter Verkerke (C++ version)
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Wednesday, January 19, 2022 at 10:25 AM.

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import ROOT

def fillWorkspace(w):
    # Create pdf and fill workspace
    # --------------------------------------------------------

    # Declare observable x
    x = ROOT.RooRealVar("x", "x", 0, 10)

    # Create two Gaussian PDFs g1(x,mean1,sigma) anf g2(x,mean2,sigma) and
    # their parameters
    mean = ROOT.RooRealVar("mean", "mean of gaussians", 5, 0, 10)
    sigma1 = ROOT.RooRealVar("sigma1", "width of gaussians", 0.5)
    sigma2 = ROOT.RooRealVar("sigma2", "width of gaussians", 1)

    sig1 = ROOT.RooGaussian("sig1", "Signal component 1", x, mean, sigma1)
    sig2 = ROOT.RooGaussian("sig2", "Signal component 2", x, mean, sigma2)

    # Build Chebychev polynomial pdf
    a0 = ROOT.RooRealVar("a0", "a0", 0.5, 0.0, 1.0)
    a1 = ROOT.RooRealVar("a1", "a1", -0.2, 0.0, 1.0)
    bkg = ROOT.RooChebychev("bkg", "Background", x, [a0, a1])

    # Sum the signal components into a composite signal pdf
    sig1frac = ROOT.RooRealVar("sig1frac", "fraction of component 1 in signal", 0.8, 0.0, 1.0)
    sig = ROOT.RooAddPdf("sig", "Signal", [sig1, sig2], [sig1frac])

    # Sum the composite signal and background
    bkgfrac = ROOT.RooRealVar("bkgfrac", "fraction of background", 0.5, 0.0, 1.0)
    model = ROOT.RooAddPdf("model", "g1+g2+a", [bkg, sig], [bkgfrac])


Create and fill workspace

Create a workspace named 'w' With CINT w could exports its contents to a same-name C++ namespace in CINT 'namespace w'. but self does not work anymore in CLING. so self tutorial is an example on how to change the code

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w = ROOT.RooWorkspace("w", True)

Fill workspace with pdf and data in a separate function

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Print workspace contents

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self does not work anymore with CLING use normal workspace functionality

Use workspace contents

Old syntax to use the name space prefix operator to access the workspace contents

d = w.model.generate(w.x,1000) r = w.model.fitTo(*d)

use normal workspace methods

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model = w["model"]
x = w["x"]

d = model.generate({x}, 1000)
r = model.fitTo(d)

old syntax to access the variable x frame = w.x.frame()

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frame = x.frame()

OLD syntax to ommit x. NB: The 'w.' prefix can be omitted if namespace w is imported in local namespace in the usual C++ way

using namespace w model.plotOn(frame) model.plotOn(frame, ROOT.RooFit.Components(bkg), ROOT.RooFit.LineStyle(ROOT.kDashed))

correct syntax

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bkg = w["bkg"]
model.plotOn(frame, Components=bkg, LineStyle="--")

Draw the frame on the canvas

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c = ROOT.TCanvas("rf509_wsinteractive", "rf509_wsinteractive", 600, 600)


Draw all canvases

In [ ]:
from ROOT import gROOT