Rooters,
Lately I've been using the very useful TProfile2D type of histogram,
and would find it very convenient to be able to use Profiles of these
histograms.
However, projections of TProfile2D's do not behave in the expected way. (I'm
using 3.05.02 on Linux)
Using the example below, a Projection of just one bin has the values
from
that bin, but no errors. It would be nice to have the errors displayed.
Next, when projecting over more than one bin, one gets the sum of the
bins included. Given that it is a Profile histogram, it would make more sense
to get the average, with the errors calculated in the same way as the original
Profile histogram.
regards,
Aaron Roodman
TProfile2D* aP2D = new TProfile2D("aP2D","test Profile",40,-4.,4.,40,-4.,4.);
for (Int_ti=0;i<10000;i++){aP2D->Fill(gRandom->Gaus(),gRandom->Gaus(),gRandom->
Gaus());}
aP2D->ProjectionX("prox",20,20)->Draw();
aP2D->ProjectionX("prox",20,21)->Draw();
_______________________________________________________________________________
Prof. Aaron Roodman Stanford Linear Accelerator Center
Stanford University E-mail: roodman@slac.stanford.edu
2575 Sand Hill Rd. Phone: 650-926-2705
MS 95 Fax: 650-926-2657
Menlo Park, CA 94025 URL: http://www.slac.stanford.edu/~roodman
_______________________________________________________________________________
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