# systematics for NLO process

I need to calculate systemics for lahpdf(265000) error vectors.

True = reweight_pdf ! Reweight to get PDF uncertainty. Should be a
! list booleans of equal length to lhaid to specify for
! which PDF set to include the uncertainties.
I turn reweight true but in result no systematics are present

run_01
p p
6500.0 x 6500.0 GeV
tag_1
433.2 ± 8

10000
parton aMC@NLO LHE summary
run_01_decayed_1
p p
6500.0 x 6500.0 GeV
tag_1
14.87 ± 0.27

10000
parton aMC@NLO LHE
shower aMC@NLO HEPMC

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Olivier Mattelaer
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 Revision history for this message Olivier Mattelaer (olivier-mattelaer) said on 2021-11-23: #1

The only information reported is the summary for the cross-section.
the additionaly weight are also present whithin the lhe file such that you can plot the diffferential cross-section with the error.

Cheers,

Olivier

 Revision history for this message Anees khan (aneeskhan) said on 2021-11-23: #2

how to plot differential cross-section with errors?
or is their any why to calculate systematics for NLO like LO?
as below
I use LO to compute cross-section which automatically give systematics for lhapdf error sets
run_01
p p
6500.0 x 6500.0 GeV
tag_1
8.692 ± 0.027 ± systematics

 Revision history for this message Olivier Mattelaer (olivier-mattelaer) said on 2021-11-23: #3

Yes you can run the exact same program as for LO to have the systematics computation at NLO.
See here:

Cheers,

Olivier

 Revision history for this message Anees khan (aneeskhan) said on 2021-11-23: #4

so it means i have to write below to lines in run card of NLO

systematics = systematics_program

['--pdf=central', '--dyn=-1,3', '--together=mur,muf'] = systematics_arguments

right??

 Revision history for this message Olivier Mattelaer (olivier-mattelaer) said on 2021-11-23: #5

And have to setup one additional parameter to include in the chef file the information needed for the systematics program to run.

Cheers,

Olivier

PS: I should check if this is still working in 3.3.0 since they have slightly change the format. So if you have issue please use our LTS version (2.9.6)

> On 23 Nov 2021, at 18:15, Anees khan <email address hidden> wrote:
>
> Question #699600 on MadGraph5_aMC@NLO changed:
>
>
> Anees khan is still having a problem:
> so it means i have to write below to lines in run card of NLO
>
> systematics = systematics_program
>
> ['--pdf=central', '--dyn=-1,3', '--together=mur,muf'] =
> systematics_arguments
>
>
> right??
>
> --

 Revision history for this message Anees khan (aneeskhan) said on 2021-11-24: #6

where is this chef file?

 Revision history for this message Olivier Mattelaer (olivier-mattelaer) said on 2021-11-24: #7

Sorry chef was a typo.
This should have been "run_card"

You also have to set the parameter
True = store_reweight_info

 Revision history for this message Anees khan (aneeskhan) said on 2021-11-24: #8

I set True = store_reweight_info
but i can't see systimatics for NLO calculations?

 Revision history for this message Olivier Mattelaer (olivier-mattelaer) said on 2021-11-24: #9

Yes that's normal those are hidden parameter.

Cheers,

Olivier

> On 24 Nov 2021, at 08:55, Anees khan <email address hidden> wrote:
>
> Question #699600 on MadGraph5_aMC@NLO changed:
>
>
> Anees khan is still having a problem:
> I set True = store_reweight_info
> but i can't see systimatics for NLO calculations?
>
> --

 Revision history for this message Anees khan (aneeskhan) said on 2021-11-24: #10

Then how can i see those hidden parameters?

 Revision history for this message Anees khan (aneeskhan) said on 2021-11-29: #11

can any one help me?

 Revision history for this message Olivier Mattelaer (olivier-mattelaer) said on 2021-11-29: #12

Sure, i have copy paste here the instruction from our webpage:

In order to use this module you have to set the run_card parameter "store_reweight_info" to True (i.e. having the following line in the run_card)

> True = store_reweight_info
This is not the default value of this parameter. If you want that this module is directly called after the event generation you have to add the following lines in the run_card:

systematics = systematics_program
parameter of the systematics module can be specified in systematics_argument for example with the following line in the run_card:

> ['--pdf=central', '--dyn=-1,3', '--together=mur,muf'] = systematics_arguments

The list of available options are the same as the one at LO (see above)

As for the LO case, a dedicated function exists in the aMC@NLO interface (available via either launch -i or via the ./bin/aMC@NLO script)

> On 29 Nov 2021, at 07:35, Anees khan <email address hidden> wrote:
>
> Question #699600 on MadGraph5_aMC@NLO changed:
>
> can any one help me?
>
> --

 Revision history for this message Olivier Mattelaer (olivier-mattelaer) said on 2021-11-29: #13

"you have to **add** the following lines in the run_card:"

Cheers,

Olivier

> On 29 Nov 2021, at 07:42, Olivier Mattelaer <email address hidden> wrote:
>
> Sure, i have copy paste here the instruction from our webpage:
>
>
>
> In order to use this module you have to set the run_card parameter "store_reweight_info" to True (i.e. having the following line in the run_card)
>
>> True = store_reweight_info
> This is not the default value of this parameter. If you want that this module is directly called after the event generation you have to add the following lines in the run_card:
>
> systematics = systematics_program
> parameter of the systematics module can be specified in systematics_argument for example with the following line in the run_card:
>
>> ['--pdf=central', '--dyn=-1,3', '--together=mur,muf'] = systematics_arguments
>
> The list of available options are the same as the one at LO (see above)
>
> As for the LO case, a dedicated function exists in the aMC@NLO interface (available via either launch -i or via the ./bin/aMC@NLO script)
>
>
>> On 29 Nov 2021, at 07:35, Anees khan <<email address hidden> <mailto:<email address hidden>>> wrote:
>>
>> Question #699600 on MadGraph5_aMC@NLO changed:
>>
>> can any one help me?
>>
>> --
>

 Revision history for this message Anees khan (aneeskhan) said on 2021-11-29: #14

an error came

INFO: Events generated
systematics run_02 --mur=0.5,1,2 --muf=0.5,1,2 --pdf=errorset
INFO: Running Systematics computation
INFO: Idle: 4, Running: 0, Completed: 0 [ current time: 17h25 ]
WARNING: program /usr/bin/python3 -O /home/anees/MG5_aMC_v3.3.0/MG5_aMC_v3_3_0/anees/bin/internal/systematics.py events.lhe.gz ./tmp_0_events.lhe.gz --mur=0.5,1,2 --muf=0.5,1,2 --pdf=errorset --start_event=0 --stop_event=2500 --result=./log_sys_0.txt --lhapdf_config=/home/anees/MG5_aMC_v3.3.0/MG5_aMC_v3_3_0/HEPTools/lhapdf6_py3/bin/lhapdf-config launch ends with non zero status: 1. Stop all computation
INFO: Running Systematics computation
Command "launch auto " interrupted with error:
KeyError : 'scalefact'
INFO:
quit
INFO:

 Revision history for this message Olivier Mattelaer (olivier-mattelaer) said on 2021-11-29: #15

Hi,

As i was expecting, this mode is not working in our 3.3.0 release, you should use our long term stable release (2.9.7) for having this mode working. (3.3.1 should have that fixed)

Cheers,

Olivier

 Revision history for this message Anees khan (aneeskhan) said on 2021-11-29: #16

yes now systematics are included but with no data in it
https://ibb.co/qpTpv96
how can i solve this now?

 Revision history for this message Anees khan (aneeskhan) said on 2021-11-29: #17

and i also need systematics after decay (in madspin card)

 Revision history for this message Anees khan (aneeskhan) said on 2021-11-30: #18

yes now systematics are included but with no data in it
https://ibb.co/qpTpv96
how can i solve this now?

The above problem is solved now,but showing systematics before decay.I also need systematics after decay
How can i do this?

 Revision history for this message Olivier Mattelaer (olivier-mattelaer) said on 2021-11-30: #19

You can just multiply by the Branching ratio (if unique) to have the result after madspin.

Cheers,

Olivier

> On 30 Nov 2021, at 07:30, Anees khan <email address hidden> wrote:
>
> Question #699600 on MadGraph5_aMC@NLO changed:
>
> yes now systematics are included but with no data in it
> https://ibb.co/qpTpv96
> how can i solve this now?
>
> The above problem is solved now,but showing systematics before decay.I also need systematics after decay
> How can i do this?
>
> --