[Rivet] Normalization issue in a Rivet STAR analysis?

[Leif Lönnblad]

On 2015-10-08 12:50, Andy Buckley wrote:
> On calling finalize() multiple times... *sigh* no, not yet. The problem
> is that finalize() calls tend to invalidate the histograms for further
> filling, hence copying of the data objects is needed before making the
> call... and the user shouldn't be aware that that is going on. It's a
> technical issue -- not complicated, but requiring some re-engineering of
> how we mix the "system" and "user" views of data objects.

I suggested a while back that rivet should explicitly separate between 
"fill" histograms and "output" histograms. The analyses would then not 
be allowed to scale/divide/whatever fill histograms in finalize(), but 
only use them read-only to produce output histograms. (And I think the 
user SHOULD be aware that this is what is going on.) This would then 
allow for calling finalize() several times, and also facilitate adding 
runs together. In the latter case it should be fairly easy to add fill 
histograms from different YODA files and then run finalize() again on 
the added histograms.

Cheers,
Leif