In This Package:

mergeFiles.py

Go to the documentation of this file.

#!/usr/bin/env python
#
# Script to add histograms from multiple ROOT files.
#
# Usage:
# % mergeFiles.py -o outfile.root infile1.root infile2.root [infile3.root ...]
#
#  This is similar to the ROOT 'hadd' function, with some key differences:
#   - Only combines histograms (no graphs or trees)
#   - If a histogram x-axis is 'time' (ie. TH1::GetTimeDisplay()==true ),
#     then that histogram is 'merged', extending the axis range and rebinning
#     if needed.

import ROOT
TFile = ROOT.TFile
TList = ROOT.TList
TH1 = ROOT.TH1
TDirectory = ROOT.TDirectory
TObject = ROOT.TObject
ROOT.gROOT.ProcessLine(".L $RUNDIAGNOSTICSROOT/share/mergeDirectories.C+")


class MergeRoot:
    """Merge histograms in ROOT files"""
    def __init__(self,inputFilenames,outputFilename):
        """Constructor"""
        self.inputFilenames = inputFilenames
        self.outputFilename = outputFilename
        self.outputFile = None
        return

    def merge(self):
        """Merge input paths to output path"""
        TH1.AddDirectory(False)
        self.outputFile = TFile(self.outputFilename, "RECREATE")
        for filename in self.inputFilenames:
            print "Processing input: ",filename
            inputFile = TFile( filename ) 
            ROOT.mergeDirectories("",inputFile,self.outputFile)
            inputFile.Close()
        #Close Output files
        self.outputFile.Write()
        self.outputFile.Close()
        return

if __name__=="__main__":
    """Process command line, merge files"""
    import sys, getopt, os
    opts, args = getopt.getopt(sys.argv[1:],"i:o:")
    print "opts = ",opts
    inFiles = []
    outFile = "merge.root"
    for opt, arg in opts:
        if opt == "-o":
            outFile = arg
    inFiles += args
    # Check for existence of input files 
    for filename in inFiles:
        if not os.path.isfile(filename):
            print "Error: '",filename,"' does not exist!"
            sys.exit(1)
    # Make sure we are merging at least 2 input files         
    if len(inFiles)<2:
        print "Usage:  % mergeFiles.py -o outfile.root infile1.root infile2.root [infile3.root ...]"
        sys.exit(1)

    # Merge files    
    merger = MergeRoot(inFiles, outFile)
    merger.merge()
    print "Done with merge"
    

---