[yt-users] convert arbitrary particle based quantities to cloud-in-cell mesh

[Matthew Turk]

Hi Brendan,

The CIC deposition routines *themselves* are subject to change and not
necessarily API stable.  You can try using them and the raw routines, but
they may be subject to changes.

-Matt

On Wed, Aug 19, 2015 at 1:02 PM, Brendan Griffen <
brendan.f.griffen at gmail.com> wrote:

> Hi Nathan,
>
> Is there an example of how one might do this for say an array which
> contains particle based x,y,z (for an arepo cell) and some arbitrary other
> quantity of the same length (e.g. HI density, velocity magnitudes etc.)?
> Seems like you can only do it if you've loaded the data through yt. I
> wanted to load in the quantities using my tools as numpy arrays then feed
> that into the deposition.
>
> Thanks.
> Brendan
>
> On Thu, Jun 25, 2015 at 11:31 AM, Nathan Goldbaum <nathan12343 at gmail.com>
> wrote:
>
>> In the latest dev version of yt, there is a
>> ds.add_deposited_particle_field function attached to all dataset instances
>> that automates the workflow Britton suggests.
>>
>>
>> On Thursday, June 25, 2015, Britton Smith <brittonsmith at gmail.com> wrote:
>>
>>> Hi Brendan,
>>>
>>> I would have a look in the yt source in yt/fields/particle_fields.py at
>>> the field functions like particle_mass and particle_cic.  They are good
>>> examples of just how the deposited fields are done.  In addition, there is
>>> a field function, _get_density_weighted_deposit_field, for doing
>>> mass-weighted deposited fields.  I think this is exactly what you're
>>> looking for.  In fact, it seems that mass-weighted velocity fields already
>>> exist as something like ("deposit", "<PTYPE>_sum_velocity_x") or
>>> ("deposit", "<PTYPE>_nn_velocity_x").  If you have multiple particle types
>>> for stars and such, they should already be defined with these fields.  This
>>> should give you a template for implementing any other fields of this type.
>>>
>>> Britton
>>>
>>> On Wed, Jun 24, 2015 at 12:28 PM, Brendan Griffen <
>>> brendan.f.griffen at gmail.com> wrote:
>>>
>>>> Hi,
>>>>
>>>> I'm looking to convert particle based quantities into a uniform grid
>>>> based quantity (arepo data is input). So say I have a collection of gas
>>>> elements with some density rho and x,y,z positions. I want to construct an
>>>> 256^3 mesh representing the cells in a mesh.
>>>>
>>>> x,y,z,rho --> cic mesh where the values at i,j,k is the smoothed
>>>> density are created by the cic algorithm
>>>>
>>>> Now, generalising this more, can I have rho to be any quantity? So now
>>>> say I have star particles which similarly have x,y,z but I want to
>>>> distribute their luminosity. Again, I want to do it for say the gas
>>>> velocity field as well. Is there any general functionality for converting
>>>> particle quantities to mesh quantites in yt with the deposit all_cic
>>>> functionality? I have a basic code for just x,y,z particle data and
>>>> distributing that based on density to a cic (see below)
>>>>
>>>> ad = pf.all_data()
>>>> level = int(math.log(ndim,2))
>>>> cg = pf.covering_grid(level=level,
>>>> left_edge=[0,0,0],dims=[ndim,ndim,ndim])
>>>> arr = cg['deposit', 'all_cic'],
>>>>
>>>> but I'm not sure what to do for the other variables. Any help is
>>>> appreciated in advance.
>>>>
>>>> Thanks.
>>>> Brendan
>>>>
>>>> _______________________________________________
>>>> yt-users mailing list
>>>> yt-users at lists.spacepope.org
>>>> http://lists.spacepope.org/listinfo.cgi/yt-users-spacepope.org
>>>>
>>>>
>>>
>> _______________________________________________
>> yt-users mailing list
>> yt-users at lists.spacepope.org
>> http://lists.spacepope.org/listinfo.cgi/yt-users-spacepope.org
>>
>>
>
> _______________________________________________
> yt-users mailing list
> yt-users at lists.spacepope.org
> http://lists.spacepope.org/listinfo.cgi/yt-users-spacepope.org
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.spacepope.org/pipermail/yt-users-spacepope.org/attachments/20150819/af07ac31/attachment.html>