Code review comment for lp:~maddevelopers/mg5amcnlo/v3_syntax_handler

Hi,

It seems to me that now the stop works correctly, in this context I do
not see a case where a Warning is necessary.

Now, if I do

set acknowledged_v3.1_syntax True --global

the codes does not stop and runs as expected.
However, if I do

generate p p > t t~ QCD=1 QED=1 [QCD]

I obtain

Interpreting 'QED=1' as 'QED<=1'
Interpreting 'QCD=1' as 'QCD<=1'
Order QED is not constrained as squared_orders. Using: QED^2=2
Order QCD is not constrained as squared_orders. Using: QCD^2=2
WARNING: Use of multiparticles is non-trivial for NLO process generation
and depends on the orders included, the process considered, as well as
the PDF set chosen. See appendix D of arXiv:1804.10017 [hep-ph] for some
guidance.
INFO: Generating FKS-subtracted matrix elements for born process: g g >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (1 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: g a >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (2 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: u u~ >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (3 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: c c~ >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (4 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: d d~ >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (5 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: s s~ >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (6 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: u~ u >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (7 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: c~ c >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (8 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: d~ d >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (9 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: s~ s >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (10 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: b b~ >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (11 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: b~ b >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (12 / 13)
INFO: Generating FKS-subtracted matrix elements for born process: a g >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (13 / 13)
INFO: Generating virtual matrix element with MadLoop for process: g g >
t t~ QCD<=2 QED<=1 QCD^2=4 QED^2=2 (1 / 13)

I do not understand if

Order QED is not constrained as squared_orders. Using: QED^2=2
Order QCD is not constrained as squared_orders. Using: QCD^2=2

is a suggestion or a description of what is happening. If it is the
latter, it is not what we want I guess. The command set
acknowledged_v3.1_syntax True --global I thought allows the expert users
to play with amplitudes and not squared orders, regardless of IR
finiteness or consistency.

On the other hand, by looking at the code generated it seems  that is
/*partially*/ doing what we expect, since virtual matrix elements are
present only in the directories P0_ag_ttx and P0_ga_ttx, that is the
code should produce the Born amplitude only for ag_ttx or ga_ttx
(although I see born.f in all folders) and builds QCD Virtuals only for
that.
I thought  the code builds also real radiations and that is the reason
why there are many more folders than ag_ttx or ga_ttx, but besides
ag_ttx or ga_ttx there is not real radiation.

In conclusion,

For the general user:

- fine, the code stops when it is required to do things with the old
syntax that are different to what one would expect from the 2018 paper.

For the expert user:

- if one types "set acknowledged_v3.1_syntax True --global" it is not
clear what is happening. Borns are produced for folders where they
should not be produced, real radiations are not present in folders where
I guess should also be present. Virtuals seems to be done correctly

Cheers
Davide

On 10.05.21 22:54, Olivier Mattelaer wrote:
> Sorry my last message was not clear.
>
> So I have update the unittest to remove the warning category.
> And also already fix the code to pass the new test.
>
> So do you see any case where a warning would be in order?
> Or do you see any additional case that my test should check?
>
> Olivier