[Rivet] aidamerge

[Hannes Jung]

Dear Hendrik & Andy

thanks a lot for your comments ... I was happy to hear that the problem cannot come from
the division of histos.... and also not from aidamerge...

... at the end it turned out that I gave a inf xsection, which then caused the problem...
so.... it was my fault....

Thanks again

cheers
Hannes

On 22.08.2011, at 17:15, Hendrik Hoeth wrote:

Hi Hannes,

Thus spake Hannes Jung (hannes.jung at cern.ch<mailto:hannes.jung at cern.ch>):

I divide 2 histograms in the code, and there could be of course a zero
in the denominator.

But the histo package should take care of this... or do you really
mean I should check every bin to make sure that there is an entry
before calling the histo divide option via:
histogramFactory().divide(histoPath("jetptl_ratio"),
*_hist_jetptl_central_ratio, *_hist_jetptl_central_only_ratio);

I'd be surprised if this causes the nans, since we already catch
division by zero in that function. So I agree, you shouldn't get an inf
or nan, but without knowledge about your code nobody can solve the
problem for you.

Some suggestions for you debugging session:

- Check that _hist_jetptl_central_ratio and
 _hist_jetptl_central_only_ratio have sensible content.
 Maybe the nans are already in there?

- The divide() function you're calling is in
 include/LWH/HistogramFactory.h, so that's a place to
 start looking.

If you find anything that looks wrong, please let us know.

Cheers,

   Hendrik

--
A man without a dream in his heart already has one foot in the grave.


***********************************************************************
Hannes Jung
Email: Hannes.Jung at cern.ch<mailto:Hannes.Jung at cern.ch>
mobile :+49 40 8998 93741
http://www.desy.de/~jung
Tel: +49 (0) 40 8998 3741 (DESY)
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