[Rivet] mcplots

[Peter Skands]

> we looked at the mcplots today, and there are a few improvements I want
> to suggest:
>
> - The error bands in the ratio plots on
>    http://mcplots.cern.ch/?query=plots,pp%2Fppbar,uemb-soft,pt,Pythia%208,
>    are asymmetric, while the reference data has symmetric errors.

Please look at the error bars again, in particular for the last few bins, which 
are the ones in question.

> - Can you plot the tick marks in the ratio plots on top of the error
>    bands, rather than below?

Yes, if ROOT had been better coded, that would be possible. As it is, I don't 
know how to do that. If anyone stumbles on a solution to this, I'd be happy to 
know.

> - Luckily my horizontal screen resolution is 1920 pixel. But on anything
>    smaller four plots next to each other aren't nice to navigate. Maybe
>    you can let them float?

That would indeed be nice. We did look into that, but were not able to do it so 
far. We made a compromise between horizontal and vertical scrolling.

> - Can you put the Rivet histogram ID in the plot, not just the analysis?
>    That would make identifying plots you are talking about in your bug
>    reports sooooo much easier.

You mean like the "d01-x01-y01" in
# BEGIN HISTOGRAM /REF/CMS_2011_S8957746/d01-x01-y01
AidaPath=/REF/CMS_2011_S8957746/d01-x01-y01
?
For aesthetical reasons, this should not be on the plots, unless we introduce 
some kind of "debug" mode of the site, which is not in the plans. In fact, I'd 
like to get rid of the SPIRES numbers as well and replace them by proper journal 
references. However, the information above *is* in our .dat files for each 
histogram, and now that we know *that* is what you need, we can simply start 
sending you that information instead in our reports. That should then still work 
for you.

> - Many plots have lousy statistics, like the 1960 GeV UE plots or ATLAS
>    minbias pT spectra. One doesn't really learn something if the error
>    bars are larger than the vertical size of the plot. Any chance you can
>    run those with better stats?

Lol, you really do like to point out the obvious :) Obviously we are working 
extremely hard on this.

Peter