Logic for creating gridpacks with 2016 PDFs

[DryRun]

I was wondering how the logic for 2016 PDFs is supposed to work in the gridpack creation scripts. Particular these lines, https://github.com/cms-sw/genproductions/blob/master/bin/MadGraph5_aMCatNLO/Utilities/gridpack_helpers.sh#L12-L23, which control the default PDFs used for 2016 vs. 2017. Should this line:

elif grep -q -e "\$DEFAULT_PDF_SETS" -e "\$DEFAULT_PDF_MEMBERS" $CARDSDIR/${name}_run_card.dat; then

be something like this instead:

elif grep -q -e "\$DEFAULT_2016_PDF_SETS" -e "\$DEFAULT_PDF_MEMBERS" $CARDSDIR/${name}_run_card.dat; then ? It seems like the first "elif" block will never be entered.

Thanks,
David

[agrohsje]

Hi @DryRun . I hope @kdlong or @qliphy can comment more on the logic. I must admit it is not clear to me how the current splitting is supposed to work.

[qliphy]

Currently for 2017/2018, PDF can be handled automatically, if one set in run_card.dat the following as in GEN recommendation:
$DEFAULT_PDF_SETS = lhaid [1]
  $DEFAULT_PDF_MEMBERS = reweight_PDF [2]

However, for 2016, one has to set it explicitly by hand as one may want a different central PDF.
In this case, as @DryRun mentioned, as there is no [1] [2] set as above,
https://github.com/cms-sw/genproductions/blob/master/bin/MadGraph5_aMCatNLO/Utilities/gridpack_helpers.sh#L18-L23
this will leave the run_card.dat as default.
On the other hand, due to the following:
https://github.com/cms-sw/genproductions/blob/master/Utilities/scripts/getMG5_aMC_PDFInputs.py#L18
https://github.com/cms-sw/genproductions/blob/master/Utilities/python/PDFSetsChooserTools.py#L10-L16
Thus at the end, the reweight PDF sets for 2016 will just follow 2017.

One indeed needs to improve a bit for 2016 case.

[kdlong]

Right. This was on my todo list for so long it fell off. If someone would like to have it, it's quite straightforward to implement, I can provide input at least.

[agrohsje]

@DryRun Would you be available to do it with the help of @kdlong ?

[DryRun]

Hi @agrohsje - sure, I'd be happy to.