yade-dev team mailing list archive

[Jerome Duriez <jerome.duriez@xxxxxxxx>]

I now think the most logical would be to keep this expression with a 
minus sign [*], but rename 'gravWork' into 'gravPotential' (like we have 
'elastPotential').

It would reconcile for me the name with the coded expression, and be 
more logical with the existence of O.energy.total() function (which sums 
all terms in O.energy and certainly is expected to be constant)


Thoughts ?

[*] 
https://gitlab.com/yade-dev/trunk/-/blob/master/pkg/dem/NewtonIntegrator.cpp#L85

------
Chargé de Recherche / Research Associate
Inrae, RECOVER
3275 route Cezanne – CS 40061 13182 Aix-en-Provence Cedex 5 FRANCE
+33 (0)4 42 66 99 21
https://www6.paca.inrae.fr/recover/membres-du-laboratoire/pages-personnelles/jerome-duriez

On 20/04/2020 10:25, Jerome Duriez wrote:
> Hi,
>
> Is there a consensus (outside myself) for the extra minus sign in 
> O.energy['gravWork'], computed in NewtonIntegrator at [*].
>
> It seems that code line was initially introduced by Vaclav in 
> GravityEngine in commit [**] (and made finally its way into 
> NewtonIntegrator).
>
> As far as I'm concerned, I can not make sense of the comment justifying 
> that sign, just above [*], neither of a consequent negative power of 
> weight during some free fall.
>
>
> Jérôme
>
>
> [*] 
> https://gitlab.com/yade-dev/trunk/-/blob/master/pkg/dem/NewtonIntegrator.cpp#L85 
>
>
> [**] 
> https://gitlab.com/yade-dev/trunk/-/commit/d41480acf2ad616268c9ed562b625952c87c98a5, 
> see also corresponding file from that time at 
> https://gitlab.com/yade-dev/trunk/-/blob/d41480acf2ad616268c9ed562b625952c87c98a5/pkg/common/GravityEngines.cpp#L33 
>
> ------
> Chargé de Recherche / Research Associate
> Inrae, RECOVER
> 3275 route Cezanne – CS 40061 13182 Aix-en-Provence Cedex 5 FRANCE
> +33 (0)4 42 66 99 21
> https://www6.paca.inrae.fr/recover/membres-du-laboratoire/pages-personnelles/jerome-duriez