RE: RE: TProfile means problem

From: Bertrand Bellenot <Bertrand.Bellenot_at_cern.ch>
Date: Tue, 19 Jul 2011 06:51:53 +0000

Hi,

See for example the "Windows" section in this page: http://root.cern.ch/drupal/content/production-version-530

Cheers, Bertrand.

From: owner-roottalk_at_root.cern.ch [mailto:owner-roottalk_at_root.cern.ch] On Behalf Of Akondi Subrahmanya Chandra Sekhar Sent: 19 July 2011 07:02
To: Snyder, Arthur E.
Cc: Rene Brun; roottalk_at_pcroot.cern.ch
Subject: Re: [ROOT] RE: TProfile means problem

Hi Guys, i am new to ROOT i want to install ROOT in my laptop windows 7x64, can any one suggest me step by step procedure (pdf), waiting for ur reply guys thanks,
chandu

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From: owner-roottalk_at_lxroot01.cern.ch<mailto:owner-roottalk_at_lxroot01.cern.ch> [owner-roottalk_at_lxroot01.cern.ch<mailto:owner-roottalk_at_lxroot01.cern.ch>] On Behalf Of Snyder, Arthur E. [snyder_at_slac.stanford.edu<mailto:snyder_at_slac.stanford.edu>] Sent: Saturday, July 09, 2011 11:40 PM
To: Rene Brun
Cc: roottalk_at_pcroot.cern.ch<mailto:roottalk_at_pcroot.cern.ch> Subject: [ROOT] TProfile means problem

Hello Rene et al.,

I'm having with |TProfile|. When I plot <y> vs. "x" with |TProfile| I get values in each x-bin that are ~2 (not exactly 2) times bigger than when I just histogram y and read the mean <y> off the histogram.

Has this happen'd before? I don't see where |TProfile| is getting the number it is plotting. It is not, e.g, the RMS. The ratio to the mean is 2.15 -- not exactly 2.0.

I tried to get the y-distribution |TProfile| uses, but can find a function that extracts it. Perhaps |TProfile| uses big y-bins and calculating means from bin centers rather than event average. Is that possible? This doesn't seem to be what the documentation says though ...

The distribution of y is steeply falling from zero -- roughly exponential. The statistics are large even in each x-bin.

?

-Arthur S.

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Received on Tue Jul 19 2011 - 08:52:00 CEST