pushing painting TH1D to it's limits

From: Damir Buskulic (buskulic@lapp.in2p3.fr)
Date: Fri Oct 22 1999 - 10:03:36 MEST


Hi Rooters,

I have a problem with painting TH1D histograms (yet another painting
problem ;-) )
It happens in our analyses that we get numbers like 1.e45 (namely, the
square of spectral density). When one wants to plot such numbers, even
contained in an array of doubles like in TH1D, one gets nothing, or
random crashes.
I suppose this has to do with the fact that all painting methods use
floats internally and are thus limited to 1e38. What would it need to
allow painting of TH1D in such, not so unusual conditions for us ?
I suppose (I have to try) that this would be possible if all internal
variables of painter where changed from Float_t to Double_t. But I fear
that one would have to change also the type of such things as the
internal variables of TAxis for example, which would lead to big changes
in I/O, not to mention a possible though small speed decrease.

Have we reached here a limitation of the ROOT painter ? TH1D is not so
useful in this particular case. Of course, one can rescale everything
down but this seems not so natural.

Any comments ?

Cheers

Damir
-- 
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| Damir Buskulic                  | Universite de Savoie/LAPP       |
|                                 | Chemin de Bellevue, B.P. 110    |
| Tel : +33 (0)450091600          | F-74941 Annecy-le-Vieux Cedex   |
| e-mail: buskulic@lapp.in2p3.fr  | FRANCE                          |
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