Fit example.
TFile** fillrandom-py.root
TFile* fillrandom-py.root
KEY: TFormula form1;1 abs(sin(x)/x)
KEY: TF1 sqroot;1 x*gaus(0) + [3]*form1
KEY: TH1F h1f;1 Test random numbers
Formula based function: sqroot
sqroot : x*gaus(0) + [3]*form1 Ndim= 1, Npar= 4, Number= 0
Formula expression:
x*[p0]*exp(-0.5*((x-[p1])/[p2])*((x-[p1])/[p2]))+[p3]*(abs(sin(x)/x))
****************************************
Minimizer is Minuit2 / Migrad
Chi2 = 198.935
NDf = 190
Edm = 1.49283e-07
NCalls = 149
p0 = 33.1658 +/- 0.545703
p1 = 4.00667 +/- 0.0165304
p2 = 0.984663 +/- 0.0128238
p3 = 63.4464 +/- 1.33233
fit1 : Real Time = 0.34 seconds Cpu Time = 0.34 seconds
import ROOT
from os import path
from ROOT import TCanvas, TFile, TPaveText
from ROOT import gROOT, gBenchmark
c1 =
TCanvas(
'c1',
'The Fit Canvas', 200, 10, 700, 500 )
c1.SetGridx()
c1.SetGridy()
c1.GetFrame().SetBorderMode(-1 )
gBenchmark.Start( 'fit1' )
File = "fillrandom-py.root"
if (ROOT.gSystem.AccessPathName(File)) :
ROOT.Info("fit1.py", File+" does not exist")
exit()
fill.ls()
sqroot = gROOT.FindObject( 'sqroot' )
sqroot.Print()
h1f = gROOT.FindObject( 'h1f' )
h1f.SetFillColor( 45 )
h1f.Fit( 'sqroot' )
fitlabel =
TPaveText( 0.6, 0.3, 0.9, 0.80,
'NDC' )
fitlabel.SetTextAlign( 12 )
fitlabel.SetFillColor( 42 )
fitlabel.ReadFile(path.join(str(gROOT.GetTutorialDir()), 'pyroot', 'fit1_py.py'))
fitlabel.Draw()
c1.Update()
gBenchmark.Show( 'fit1' )
Option_t Option_t SetFillColor
A ROOT file is an on-disk file, usually with extension .root, that stores objects in a file-system-li...
A Pave (see TPave) with text, lines or/and boxes inside.
- Author
- Wim Lavrijsen
Definition in file fit1.py.