'ORGANIZATION AND SIMULTANEOUS FITS' RooFit tutorial macro #508
RooArgSet and RooArgList tools and tricks
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, April 17, 2024 at 11:19 AM.
from __future__ import print_function
import ROOT
Create some variables
a = ROOT.RooRealVar("a", "a", 1, -10, 10)
b = ROOT.RooRealVar("b", "b", 2, -10, 10)
c = ROOT.RooRealVar("c", "c", 3, -10, 10)
d = ROOT.RooRealVar("d", "d", 4, -10, 10)
x = ROOT.RooRealVar("x", "x", 0, -10, 10)
c.setError(0.5)
a.setConstant()
b.setConstant()
Create a category
e = ROOT.RooCategory("e", "e")
e.defineType("sig")
e.defineType("bkg")
False
Create a pdf
g = ROOT.RooGaussian("g", "g", x, a, b)
[#0] WARNING:InputArguments -- The parameter 'b' with range [-10, 10] of the RooGaussian 'g' exceeds the safe range of (0, inf). Advise to limit its range.
A ROOT.RooArgSet is a set of RooAbsArg objects. Each object in the set must have a unique name
Set constructors exists with up to 9 initial arguments
s = ROOT.RooArgSet(a, b)
At any time objects can be added with add()
s.add(e)
True
Add up to 9 additional arguments in one call s.add(ROOT.RooArgSet(c, d))
s.add(c)
s.add(d)
True
Sets can contain any type of RooAbsArg, pdf and functions
s.add(g)
True
Remove element d
s.remove(d)
True
You can look up objects by name
aptr = s.find("a")
Construct a subset by name
subset1 = s.selectByName("a,b,c")
Construct asubset by attribute
subset2 = s.selectByAttrib("Constant", ROOT.kTRUE)
Construct the subset of overlapping contents with another set
s1 = ROOT.RooArgSet(a, b, c)
s2 = ROOT.RooArgSet(c, d, e)
subset3 = s1.selectCommon(s2)
Create a RooArgSet that owns its components A set either owns all of its components or none, so once addOwned() is used, add() can no longer be used and will result in an error message
ac = a.clone("a")
bc = b.clone("b")
cc = c.clone("c")
s3 = ROOT.RooArgSet()
s3.addOwned(ROOT.RooArgSet(ac, bc, cc))
s3.addOwned(ac)
s3.addOwned(bc)
s3.addOwned(cc)
Another possibility is to add an owned clone of an object instead of the original s3.addClone(ROOT.RooArgSet(d, e, g))
s3.addClone(d)
s3.addClone(e)
s3.addClone(g)
A clone of a owning set is non-owning and its contents is owned by the originating owning set
sclone = s3.Clone("sclone")
To make a clone of a set and its contents use the snapshot method
sclone2 = s3.snapshot()
If a set contains function objects, the head node is cloned in a snapshot. To make a snapshot of all servers of a function object do as follows. The result of a RooArgSet snapshot with deepCloning option is a set of cloned objects, all their clone (recursive) server dependencies, together form a self-consistent set that is free of external dependencies
sclone3 = s3.snapshot(ROOT.kTRUE)
Inline printing only show list of names of contained objects
print("sclone = ", sclone)
sclone = { @0x9673f50, @0x9673f58, @0x9673f60, @0x9673f68, @0x9673f70, @0x9673f78 }
Plain print shows the same, by name of the set
sclone.Print()
RooArgSet::sclone = (a,b,c,d,e,g)
Standard printing shows one line for each item with the items name, name and value
sclone.Print("s")
1) RooRealVar:: a = 1 2) RooRealVar:: b = 2 3) RooRealVar:: c = 3 +/- 0.5 4) RooRealVar:: d = 4 5) RooCategory:: e = sig(idx = 0) 6) RooGaussian:: g = 0.882497
Verbose printing adds each items arguments, and 'extras' as defined by the object
sclone.Print("v")
1) 0x92cd460 RooRealVar:: a = 1 C L(-10 - 10) "a" 2) 0x9653c70 RooRealVar:: b = 2 C L(-10 - 10) "b" 3) 0x95a4a10 RooRealVar:: c = 3 +/- 0.5 L(-10 - 10) "c" 4) 0x95c7460 RooRealVar:: d = 4 L(-10 - 10) "d" 5) 0x963de60 RooCategory:: e = sig(idx = 0) "e" 6) 0x9671b20 RooGaussian:: g[ x=x mean=a sigma=b ] = 0.882497 "g"
List constructors exists with up to 9 initial arguments
l = ROOT.RooArgList(a, b, c, d)
Lists have an explicit order and allow multiple arguments with the same name
l.add(ROOT.RooArgList(a, b, c, d))
True
Access by index is provided
arg4 = l.at(4)
Draw all canvases
from ROOT import gROOT
gROOT.GetListOfCanvases().Draw()