[Rivet] Question about correlated errors

[Andy Buckley]

On 06/10/14 20:19, Stephen Mrenna wrote:
> Hi,
> I have a colleague from GENIE who has a question about
> storing data in RIVET.
> 
> I wanted to make sure I had the correct answer, lest I pass
> on misinformation.
> 
> So, currently, YODA in RIVET does not handle bin-to-bin correlated
> errors?  Is there any prospect for this?  Of course, the user would
> have to figure out what to do with it.

Hi Steve,

We recently put correlated error treatment into Professor, i.e. to
handle correlations between the bins *after* Rivet. There's at least two
ways to encode bin-to-bin correlations and we preferred to allow
Professor to read both kinds from dedicated ASCII files and just
construct a bog standard matrix from that info for computing chi2s. We
didn't do it as a YODA type a) for flexibility, and b) because it seemed
like a real can of worms in general!

I don't think there is any much better / more standard approach right
now, especially since HepData also only stores correlation matrices as
user supplied text files without a standard format.

Andy

-- 
Dr Andy Buckley, Royal Society University Research Fellow
Particle Physics Expt Group, University of Glasgow / PH Dept, CERN