Gabriele Cosmo
39 lines
1015 B
C++
39 lines
1015 B
C++
// *********************************************************************
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// To execute this macro under ROOT after your simulation ended,
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// 1 - launch ROOT (usually type 'root' at your machine's prompt)
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// 2 - type '.X spectrum.C' at the ROOT session prompt
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// 3 - OR type directly 'root spectrum.C'
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// this will generate an output energy spectrum spectrum.txt,
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// according to selected statistics and distribution
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// (energy unit assumed by svalue example: eV)
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// *********************************************************************
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{
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gROOT->Reset();
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// 1) SELECT number of values to shoot
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int nbValues = 100;
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//
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double value;
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TNtuple * ntuple = new TNtuple ("","","value");
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FILE * fp = fopen("spectrum.txt","w");
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TRandom r;
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for (int i=0;i<nbValues;i++)
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{
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// 2) SELECT distribution
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// here Gaussian with mean, sigma
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// see https://root.cern/doc/master/classTRandom.html
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value = r.Gaus(1.,0.1);
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//
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ntuple->Fill(value);
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fprintf(fp,"%f \n",value);
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}
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fclose(fp);
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ntuple->Draw("value");
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}
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