yade-dev team mailing list archive

[Christian Jakob <jakob@xxxxxxxxxxxxxxxxxxx>]

Jan, Anton and Bruno,

Thank you very much for your comments.

I want to have a command, that can create 20 % clumps of type A (e.g.  
peanuts), 30 % clumps of type B (e.g. dyads), ... and so on. Also it  
should be possible to create clumps and spheres with this command  
(e.g. 20 % clumps, 80 % spheres).

sp.makeClumpCloud always creats 100 % clumps. Also all clumps seem to  
be equal in size, right? But it is nearest to want I want.
sp.makeCloud always creates 100 % spheres.

So I wanted to write a replaceByClumps() method in yadeWrapper, that  
replaces given amount of EXISTING particles by clumps (using  
template(s)).

I see, that ClumpTemplate is not really needed ...
But I do not see how to combine makeCloud and makeClumpCloud ...
I think the only way to do this is by following procedure:

1. create spheres (e.g. with makeCloud() and SpherePack())
2. create templates (new method needed?)
3. replaces spheres by clumps (using templates), whereby clump volume  
== sphere volume

@jan:

rads = [1,1]
poss = [(1,1,1),(0,0,0)]
spheres = [utils.sphere(pos,rad) for pos,rad in zip(poss,rads)]
O.bodies.appendClumped(spheres)

This is not what I want: rads and poss are absolute values, not relative ones!

For better understanding, I give you some PFC code and a picture (see  
attachment: spheres in black, dyads in blue, peanuts in orange, sticks  
in red).

;############ code for PFC 4.0:

; generate balls:

gen id = 1,500 rad .006 .015 x 0 .24 y 0 .24 z 0 .24
prop dens = 1000 kn = 1e4 ks = .5e4 fric = .5

; create clump templates:
clump template make dyad 2 radii 1.0 1.0 pos (1 0 0) (0 0 0)

clump template make peanut 3 radii .5 1 .5 pos (-1 0 0) (0 0 0) (1 0 0)

clump template make stick 5 radii 1.0 1.0 1.0 1.0 1.0  &
                              pos   (1.0,0.0,0.0)        &
                                    (2.0,0.0,0.0)        &
                                    (3.0,0.0,0.0)        &
                                    (4.0,0.0,0.0)        &
                                    (5.0,0.0,0.0)
; replace balls by clumps:

clump replace 3 dyad,.3 peanut,.2 stick,.1
;-> 30 percent dyads, 20 percent peanuts, 10 percent sticks (, 40  
percent spheres)


Regards,

Christian.


Zitat von Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx>:

> You have to make the class inherit from "Serializable" if you want to
> handle it easily in python (using all the macros that yade defines). You
> could use Body.hpp as an example.
>
> As for the user's side, it make no difference if the function is
> implemented in c++ or python (but the latest is sometimes more "light
> weight" for the devs). See for instance, the source file
> py/bodiesHandling.py.
> Saving them with O.save sounds a little bit involved, since templates
> are not bodies of the simulation and only them are saved currently.
>
>
> > in hpp. How can I set the length of the vector, after construction of
> the object in makeClumpTemplate() in yadeWrapper ?
> > shared_ptr<ClumpTemplate> ct=shared_ptr<ClumpTemplate>(new
> ClumpTemplate());
> > ct->rad ???
> > ct->pos ???
>
> The vector will have null length by default, which should be ok.
> If you register the vectors using python binding (like e.g. "ids" in
> PartialEngine), you should be able to modify the list like this:
> ct.rad.append(x) #or
> ct.rad=[1,1,1]
>
> Still, I don't see why there is a pointer to a template in the template.
>
> Note also that the current interface uses something quite similar to a
> template. In triax-tutorial/script1.py, you find this:
>
> ## define a unique clump type (we could have many, see clumpCloud
> documentation)
>   
> c1=pack.SpherePack([((-0.2*mean_rad,0,0),0.5*mean_rad),((0.2*mean_rad,0,0),0.5*mean_rad)])
>  ## generate positions and input them in the simulation
>  sp.makeClumpCloud(mn,mx,[c1],periodic=False)
>
> c1 is a sort of template, isn't it? So if I understand correctly you
> want something that would take c1 but would also be more flexible (i.e.
> that would not require one to use ClumpCloud)?
>
> Bruno
>
>
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