fix: errorbar width for ATLAS/LHCb styles

[andrzejnovak]

As we can now see in the docs both ATLAS and LHCb styles exhibit a strange behaviour for errorbars with histtype='step' where these are imo too thick.

At first I wondered if this is for data-like plots, but histtype='errorbar' doesn't have this behaviour

@jonas-eschle @matthewfeickert can you comment on LHCb/ATLAS sides if this is intended behaviour?

[matthewfeickert]

@andrzejnovak This isn't happening with the CMS style? Do you know what specifically in the style sheets is being pulled in to decorate the error bars for step?

[andrzejnovak]

I suspect it's

mplhep/src/mplhep/styles/atlas.py

Line 110 in 9b81c76

"lines.linewidth": 2,

and the discrepancy exists bc the stairs artist running under histtype='step' is not governed by "lines.[stuff]" bc it's a patch, while the errorbars we franken plot over it are. Haven't tested this though.

[matthewfeickert]

The linewidth setting for the ATLAS style

mplhep/src/mplhep/styles/atlas.py

Line 110 in 9b81c76

"lines.linewidth": 2,

was added by @kratsg in #239. @kratsg, I think you were just porting the existing ATLAS style stuff from ROOT. Not sure if you have any thoughts.

[kratsg]

I was just porting over the ATLAS style, but this had matched.

[jonas-eschle]

Hm, interesting find, thanks for bringing it up! I wasn't aware of this and I don't thing people in LHCb often use the step but rarther the "errorbar". Since step is denser overall compared to errorbar, I actually don't mind the look.