automatic scale uncertainties for HwU plots broken in v3.x.x

[Rikkert Frederix]

Hi Folks,

I am running 3.4.0 (bzr) and I am starting to suspect that the "show scale uncertainty" feature in the HwU module may be broken. By default, they are not showing on my histograms and when I explicitly call for them,

$ python ./madgraph/various/histograms.py ./.../Events/.../plot_PYTHIA8_1_0.HwU --titles=my_title --out=my_title --only_scale

I do not get a histogram without uncertainties. When I try alternative options, such as

--keep_all_weights --variations=['scale'] --band=['scale']

I get the same behavior. However, when I do 'stat' or 'pdf', I get the correct behavior.

Digging around a bit, I am wondering if the scale variation *headers* are being correctly written to the initial HwU file. They seem to differ from the PDF variation headers (no @aux tag). This is the top of my HwU file:

$ more Events/.../plot_PYTHIA8_1_0.HwU
##& xmin & xmax & central value & dy & tag= 0 dyn= -1 muR=0.10000E+01 muF=0.10000E+01 & tag= 0 dyn= -1 muR=0.20000E+01 muF=0.10000E+01 & tag=
 0 dyn= -1 muR=0.50000E+00 muF=0.10000E+01 & tag= 0 dyn= -1 muR=0.10000E+01 muF=0.20000E+01 & tag= 0 dyn= -1 muR=0.20000E+01 muF=0.20000E+01 & tag=
        0 dyn= -1 muR=0.50000E+00 muF=0.20000E+01 & tag= 0 dyn= -1 muR=0.10000E+01 muF=0.50000E+00 & tag= 0 dyn= -1 muR=0.20000E+01 muF=0.50000E+00 & tag
= 0 dyn= -1 muR=0.50000E+00 muF=0.50000E+00 & tag= 800 dyn= -1 muR=0.10000E+01 muF=0.10000E+01 & tag= 800 dyn= -1 muR=0.20000E+01 muF=0.10000E+0
1 & tag= 800 dyn= -1 muR=0.50000E+00 muF=0.10000E+01 & tag= 800 dyn= -1 muR=0.10000E+01 muF=0.20000E+01 & tag= 800 dyn= -1 muR=0.20000E+01 muF=0.2
0000E+01 & tag= 800 dyn= -1 muR=0.50000E+00 muF=0.20000E+01 & tag= 800 dyn= -1 muR=0.10000E+01 muF=0.50000E+00 & tag= 800 dyn= -1 muR=0.20000E+01
muF=0.50000E+00 & tag= 800 dyn= -1 muR=0.50000E+00 muF=0.50000E+00 & tag= 802 dyn= -1 muR=0.10000E+01 muF=0.10000E+01 & tag= 802 dyn= -1 muR=0.200
00E+01 muF=0.10000E+01 & tag= 802 dyn= -1 muR=0.50000E+00 muF=0.10000E+01 & tag= 802 dyn= -1 muR=0.10000E+01 muF=0.20000E+01 & tag= 802 dyn= -1 mu
R=0.20000E+01 muF=0.20000E+01 & tag= 802 dyn= -1 muR=0.50000E+00 muF=0.20000E+01 & tag= 802 dyn= -1 muR=0.10000E+01 muF=0.50000E+00 & tag= 802 dyn=
  -1 muR=0.20000E+01 muF=0.50000E+00 & tag= 802 dyn= -1 muR=0.50000E+00 muF=0.50000E+00 & delta_pdf_cen NNPDF31_nlo_as_0118_luxqed @aux & delta_pdf_min NNPDF31_nlo_as_011
8_luxqed @aux & delta_pdf_max NNPDF31_nlo_as_0118_luxqed @aux &

... and this continues

For the record, the first entries for my histogram are filled:
<histogram> 10 "total rate [pb] |X_AXIS@LIN |Y_AXIS@LOG |TYPE@BASE|#1"
  +0.0000000e+00 +1.0000000e+00 +4.5392020e-07 +2.4351286e-09 +4.5392493e-07 ... ... ..

can someone verify / check / confirm this?

cheers
richard

[Rikkert Frederix (frederix)]

The automatic scale uncertainty plots are broken in v3.x.x. The reason that from v3.x.x onward, the plots are filled separately for each coupling order, allowing for easier separation of the various orders. This is indeed something that needs to be fixed. I'll file a bug report.