[yt-users] RFC: RAMSES field aliases in yt-3.0

[Matthew Turk]

Hi Sam,

This looks great.  Any chance you could add this to the
yt/frontends/ramses/definitions.py file as a function, issue a pull
request, and we'll get your name in the commit log?  I'll then modify
it to fit in and we'll use it as fallback when fields are specified.

-Matt

On Mon, Nov 25, 2013 at 1:39 PM, Sam Geen <samgeen at astro.ox.ac.uk> wrote:
> I've hacked up a simple example of what I mean (attached).
>
>
> On 25/11/13 17:50, Nathan Goldbaum wrote:
>
> Matt's opened a PR for this here:
>
> https://bitbucket.org/yt_analysis/yt-3.0/pull-request/140/adding-field_aliases-to-ramses-datasets/diff
>
> Sam, if you could enumerate how to map from the boolean flags you're
> suggesting to a final field list, I think that would help immensely.
>
>
> On Mon, Nov 25, 2013 at 8:42 AM, Sam Geen <samgeen at astro.ox.ac.uk> wrote:
>>
>> Yes and no. NVAR must be big enough, but it can be bigger than necessary
>> (I think); it's a Makefile setting when compiling Ramses. You can guarantee
>> that the first 4 variables are the same, but after that I suspect the best
>> approach is to use boolean flags to specify whether the run contains MHD,
>> RHD, metals, etc. Normally it's a good guess that 5 is pressure and 6 (if it
>> exists) is metals, but as I said it seems like MHD puts the B-field before
>> pressure and metallicity.
>>
>>
>> On 25/11/13 17:36, Nathan Goldbaum wrote:
>>
>> Does that mean that it should be possible to infer the field list from
>> NVAR alone?
>>
>>
>> On Mon, Nov 25, 2013 at 8:29 AM, Sam Geen <samgeen at astro.ox.ac.uk> wrote:
>>>
>>> For MHD, the variables stored are the B-field strengths on the faces of
>>> each cell - the fields in order are: (1) density, (2-4) [x,y,z] velocity,
>>> (5-7) [x,y,z] B-field left, (8-10) [x,y,z] B-field right, (11) pressure
>>> (thermal + MHD), then (12+) any passive scalars (metals, etc) - see
>>> mhd/output_hydro.f90. Note that the MHD module adds 3 variables, so the
>>> number of variables will be nvar+3.
>>>
>>> For RHD (Joki Rosdahl's M1 method implementation, at least - someone else
>>> will have to help with the ATON version), there is a separate "rt_" output
>>> file for each CPU (like the hydro/amr/particles), as well as a separate info
>>> file (there is a bitbucket link on the Ramses homepage if you want to see
>>> what the latest version of the code does in detail). The RHD module divides
>>> photons into "nGroups" different flux bins; for each bin, it writes a photon
>>> density and then a flux vector. nGroups is stored in the rt info file;
>>> nrtvar is written to the rt_ binary file, but this is (I think) a Makefile
>>> setting and not guaranteed to be nGroups/(1+ndim) (the user is, I believe,
>>> normally free to waste memory by allocating more variables than they need).
>>> For details it might be easiest to download the latest code and look at the
>>> code in the folder rt/, or ask Romain or Joki Rosdahl directly.
>>>
>>> (Feel free to correct me if any of this is wrong!)
>>>
>>> I agree that setting the default to the standard five (perhaps some
>>> boolean variables for common configurations such as metals, RHD, MHD, etc)
>>> and then letting users set or add their own fields by hand if they need to
>>> is a good approach.
>>>
>>>
>>> On 25/11/13 16:23, Matthew Turk wrote:
>>>>
>>>> Hi all, especially RAMSES users,
>>>>
>>>> I'm setting up aliases to make it easier to load RAMSES datasets that
>>>> have different field configurations.
>>>>
>>>> Right now, to specify a different set of fields, you have to do:
>>>>
>>>> pf = load( ... , fields = [ "Density", "x-velocity", ...])
>>>>
>>>> I am going to change this to add on different field configurations
>>>> that can be specified with just a string.  For instance:
>>>>
>>>> pf = load(..., fields = "standard_five")
>>>>
>>>> I'm wondering what the different configurations are.  I have these two:
>>>>
>>>> standard_five: Density, x-velocity, y-velocity, z-velocity, Pressure
>>>> standard_six: Density, x-velocity, y-velocity, z-velocity, Pressure,
>>>> Metallicity
>>>>
>>>> But for MHD and RHD, what are the additional fields that should be
>>>> added, and in what order?  And are there other common configurations
>>>> that should be aliased?
>>>>
>>>> If we can come up with a set of aliases that match most use cases,
>>>> that'd work quite well.  I'm going to issue a PR for this shortly, and
>>>> hopefully it will make everybody's life a bit easier.
>>>>
>>>> -Matt
>>>> _______________________________________________
>>>> 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
>>
>
>
>
> _______________________________________________
> 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
>