Code review comment for lp:~maddevelopers/mg5amcnlo/python_syscalc

> I know what I meant was that if I don't have lhapdf (or only lhapdf5) on my
> system, then systematics crashes with the following message:

ok this should be fixed now.

> Ok, now at NLO, I crash on:
> AttributeError: 'Event' object has no attribute 'nloweight'
>

This is because, you didnot put 'store_rwgt_info' on True in the NLo run_card.
Impossible to compute systematics in that case.
I have put in place a nicer error message for that situation.

> This happened both with and without PDF variations in my generation (I assume
> you require the user to having generated events with both variations turned
> on, it would be great if you could safe-check this).

No you can have both variation turned off.

> By the way, additional general question:
> If there is already a bunch of weights in the event, but only some are missing
> given the inputs provided to 'systematics', will you recompute all of them or
> do you automatically filter them out?
> It's ok if you recompute all of them, but I was wondering if you had optimized
> this bit.

No I'm not smart at all on that point of view, I recompute them and add them to the event file.

Cheers,

Olivier