def rooFit207():
print ">>> setup model signal components: gaussians..."
x = RooRealVar("x","x",0,10)
mean = RooRealVar("mean","mean of gaussians",5)
sigma = RooRealVar("sigma","width of gaussians",0.5)
sig = RooGaussian("sig","Signal",x,mean,sigma)
print ">>> setup model background components: Chebychev polynomial plus exponential..."
a0 = RooRealVar("a0","a0",0.5,0.,1.)
a1 = RooRealVar("a1","a1",-0.2,0.,1.)
bkg1 = RooChebychev("bkg1","Background 1",x,RooArgList(a0,a1))
alpha = RooRealVar("alpha","alpha",-1)
bkg2 = RooExponential("bkg2","Background 2",x,alpha)
bkg1frac = RooRealVar("bkg1frac","fraction of component 1 in background",0.2,0.,1.)
bkg = RooAddPdf("bkg","Signal",RooArgList(bkg1,bkg2),RooArgList(bkg1frac))
print ">>> sum signal and background component..."
bkgfrac = RooRealVar("bkgfrac","fraction of background",0.5,0.,1.)
model = RooAddPdf("model","g1+g2+a",RooArgList(bkg,sig),RooArgList(bkgfrac))
# Create dummy dataset that has more observables than the above pdf
y = RooRealVar("y","y",-10,10)
data = RooDataSet("data","data",RooArgSet(x,y))
# Basic information requests:"
print ">>> get list of observables of pdf in context of a dataset..."
# Observables are define each context as the variables
# shared between a model and a dataset. In this case
# that is the variable 'x'
model_obs = model.getObservables(data) # RooArgSet
model_obs.Print('v')
print "\n>>> get list of parameters..."
# Get list of parameters, given list of observables
model_params = model.getParameters(RooArgSet(x)) # RooArgSet
print ">>> model_params.getStringValue(\"a0\") = %s" % (model_params.getStringValue("a0"))
print ">>> model_params.getRealValue(\"a0\") = %s" % (model_params.getRealValue("a0"))
print ">>> model_params.find(\"a0\").GetName() = %s" % (model_params.find("a0").GetName())
print ">>> model_params.find(\"a0\").getVal() = %s" % (model_params.find("a0").getVal())
# print ">>> for param in model_params:"
# for param in model_params.():
# print ">>> %s"%(model_params.first())
# print ">>> %s"%(model_params.first())
# model_params.selectByName("a*").Print('v')
model_params.Print('v')
print "\n>>> get list of parameters of a dataset..."
# Gives identical results to operation above
model_params2 = model.getParameters(data) # RooArgSet
model_params2.Print()
print "\n>>> get list of components..."
# Get list of component objects, including top-level node
model_comps = model.getComponents() # RooArgSet
model_comps.Print('v')
print "\n>>> modifications to structure of composites..."
sigma2 = RooRealVar("sigma2","width of gaussians",1)
sig2 = RooGaussian("sig2","Signal component 1",x,mean,sigma2)
sig1frac = RooRealVar("sig1frac","fraction of component 1 in signal",0.8,0.,1.)
sigsum = RooAddPdf("sigsum","sig+sig2",RooArgList(sig,sig2),RooArgList(sig1frac))
print ">>> construct a customizer utility to customize model..."
cust = RooCustomizer(model,"cust")
print ">>> instruct the customizer to replace node 'sig' with node 'sigsum'..."
cust.replaceArg(sig,sigsum)
# Build a clone of the input pdf according to the above customization
# instructions. Each node that requires modified is clone so that the
# original pdf remained untouched. The name of each cloned node is that
# of the original node suffixed by the name of the customizer object
#
# The returned head node own all nodes that were cloned as part of
# the build process so when cust_clone is deleted so will all other
# nodes that were created in the process.
cust_clone = cust.build(kTRUE) # RooAbsPdf
# Print structure of clone of model with sig->sigsum replacement.
cust_clone.Print("t")
# delete clone
del cust_clone
