[yt-users] Analyzing SPH data

Alankar Dutta dutta.alankar at gmail.com
Fri Mar 3 23:32:43 PST 2017


Hello,

This is only one part of the multipart snapshot of the simulation. I am
sending you the header information from the snapshot file:

{'O0': 0.27500000000000002,
 'Ol': 0.72499999999999998,
 'boxsize': 100000.0,
 'flag_age': 1,
 'flag_cooling': 1,
 'flag_delaytime': 0,
 'flag_fb': 1,
 'flag_fh2': 0,
 'flag_metals': 1,
 'flag_potential': 3,
 'flag_sfr': 1,
 'flag_tmax': 0,
 'h': 0.70199999999999996,
 'massTable': array([ 0.        ,  0.00110449,  0.        ,  0.
,  0.        ,  0.        ]),
 'nbndry': 76247,
 'nbulge': 0,
 'ndisk': 0,
 'ndm': 1459617792,
 'nfiles': 1024,
 'ngas': 1343721867,
 'npartThisFile': array([10045237, 10239661,        0,        0,
451148,       67], dtype=uint32),
 'npartTotal': array([1343721867, 1459617792,          0,          0,
503500456,
             76247], dtype=uint32),
 'npartTotalHW': array([1, 1, 0, 0, 0, 0], dtype=uint32),
 'nstar': 503500456,
 'redshift': 1.0000000010567627,
 'rhocrit': 2.707660428120944e-29,
 'time': 0.49999999973580939}



I extracted this information using a different python program.

Alankar Dutta

On Sat, Mar 4, 2017 at 12:45 PM, Nathan Goldbaum <nathan12343 at gmail.com>
wrote:

>
>
> On Sat, Mar 4, 2017 at 12:25 AM, Nathan Goldbaum <nathan12343 at gmail.com>
> wrote:
>
>>
>>
>> On Sat, Mar 4, 2017 at 12:13 AM, Alankar Dutta <dutta.alankar at gmail.com>
>> wrote:
>>
>>> Hello,
>>>
>>> Modifying the GADGET simulation isn't possible the moment because it has
>>> already been developed by someone else who has a paper  published  on this
>>> simulation and I want to use that simulation  snapshots to make mock xray
>>> map from it.
>>>
>>
>> I'm talking about modifying yt, not Gadget.
>>
>> Is the file you attached to your other e-mail just a single file in a
>> multi-file dataset? How large is the full dataset? Do you not have a way to
>> produce a full dataset in this output format that's not prohibitively large?
>>
>
> I've opened a pull request that allows me to do IO on the data you
> attached: https://bitbucket.org/yt_analysis/yt/pull-requests/2537
>
> This allows me to read your data in, getting sensible values for e.g.
> position. I suspect we're not using the correct field specification because
> I see this warning:
>
> yt : [WARNING  ] 2017-03-04 01:06:09,109 Your Gadget-2 file may have extra
> columns or different precision! (1814947576 file vs 1486279952 computed)
>
> yt supports a number of field specifications out of the box, see:
>
> https://bitbucket.org/yt_analysis/yt/src/3eca2ae80ab14a48b643d3055d7d3c
> 0933fa77ae/yt/frontends/gadget/definitions.py?at=yt&
> fileviewer=file-view-default#definitions.py-50
>
> Do you happen to know which fields are in your output file?
>
>
>>
>>
>>>
>>>
>>> Alankar Dutta
>>>
>>> On Mar 4, 2017 11:38 AM, "Nathan Goldbaum" <nathan12343 at gmail.com>
>>> wrote:
>>>
>>>> I think the most straightforward thing to do here is to fix the Gadget
>>>> frontend so it properly reads in gadget binary data with positions written
>>>> in double precision.
>>>>
>>>> Is there any chance you can generate a smallish test dataset in your
>>>> Gadget output format that we can use for debugging purposes? With that
>>>> available it should be straightforward to add support. You can share the
>>>> dataset using the yt curldrop (https://docs.hub.yt/services.
>>>> html#curldrop) or a cloud filesharing service like dropbox or google
>>>> drive.
>>>>
>>>> Unfortunately there isn't a way to load SPH data without a full-fledged
>>>> frontend right now.
>>>>
>>>> We do have a load_particles function which allows creating a dataset
>>>> from particle data loaded as numpy arrays, but it's currently not possible
>>>> to use it to load SPH data.
>>>>
>>>> I'm currently actively working on improving support for SPH data in yt
>>>> and adding the ability to load SPH data with load_particles is one of the
>>>> things I've added in that branch of the code. Hopefully this work will be
>>>> stabilized sometime in the next few months.
>>>>
>>>>
>>>>
>>>> On Fri, Mar 3, 2017 at 11:45 PM, Alankar Dutta <dutta.alankar at gmail.com
>>>> > wrote:
>>>>
>>>>> Hello yt-community,
>>>>>
>>>>> I am a beginner on yt. I have an array of data which I have read from
>>>>> a Gadget simulation snapshot. It is not directly supported by yt at present
>>>>> (I have ensured this by already discussing this issue in the community
>>>>> before). The array has position,velocity, density, mass, internal energy
>>>>> and smoothing length information on the gas particles. Now how can I use
>>>>> this to make the slice plots or other useful visualizations?
>>>>>
>>>>> Alankar Dutta,
>>>>> Third year Undergraduate,
>>>>> Physics Department,
>>>>> Presidency University, India
>>>>>
>>>>> _______________________________________________
>>>>> 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
>>>
>>>
>>
>
> _______________________________________________
> 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/20170304/b06f1fea/attachment.html>


More information about the yt-users mailing list