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hist000_TH1_first.py
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## \file
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## \ingroup tutorial_hist
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## Hello World example for TH1
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##
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## Shows how to create, fill and write a histogram to a ROOT file.
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##
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## \macro_code
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## \macro_output
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##
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## \date November 2024
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## \author Giacomo Parolini (CERN)
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import
ROOT
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# Open the file to write the histogram to
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with
ROOT.TFile.Open
(
"outfile.root"
,
"RECREATE"
)
as
outFile:
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# Create the histogram object
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# There are several constructors you can use (see TH1). In this example we use the
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# simplest one, accepting a number of bins and a range.
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histogram =
ROOT.TH1D
(
"histogram"
,
"My first ROOT histogram"
, nbinsx = 30, xlow = 0.0, xup = 10.0)
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# Fill the histogram. In this simple example we use a fake set of data.
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# The 'D' in TH1D stands for 'double', so we fill the histogram with doubles.
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# In general you should prefer TH1D over TH1F unless you have a very specific reason
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# to do otherwise.
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values = [1, 2, 3, 3, 3, 4, 3, 2, 1, 0]
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for
val
in
values:
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histogram.Fill
(val)
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# Write the histogram to `outFile`.
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outFile.WriteObject
(histogram,
histogram.GetName
())
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# When `with` block exits, `outFile` will close itself and write its contents to disk.
TRangeDynCast
ROOT::Detail::TRangeCast< T, true > TRangeDynCast
TRangeDynCast is an adapter class that allows the typed iteration through a TCollection.
Definition
TCollection.h:358
tutorials
hist
hist000_TH1_first.py
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