[yt-users] error in the field SoundSpeed?

[Matthew Turk]

Hi Luigi,

What I think might be happening is that your field ("ThermalEnergy" is
the one that you can't access, right?) is being added to the universal
container, which is less specific than the Enzo-specific container;
ThermalEnergy is nominally defined in the Enzo-specific container, so
it wins.  Try changing add_field to add_enzo_field and see if that
helps out.  If you want to redefine a field that is *in* the data
output, that is trickier, as it requires also removing the item from
the list of 'in the data' fields with
"pf.h.field_list.pop(pf.h.field_list.index('whatever'))".

The field stuff has grown to the point where it no longer scales in
the human dimension.  I think this will be a target of a cleanup in
the near future.  Britton and I have been working to expand testing
coverage and to move to a new scheme of binary-diff testing of
results; this will help us to refactor things like the field
containers.

-Matt

On Tue, May 24, 2011 at 5:36 AM, Luigi Iapichino
<luigi at ita.uni-heidelberg.de> wrote:
> Hi Matt,
>
> thanks for the suggestions. I added to my file ~/.yt/my_plugins.py the
> following lines:
>
> def _ThermalEnergy(field, data):
>    if data.pf["HydroMethod"] == 2:
>        return data["Total_Energy"]
>    else:
>        if data.pf["DualEnergyFormalism"]:
>            return data["GasEnergy"]
>        else:
>            return data["Total_Energy"] - 0.5*(
>                   data["x-velocity"]**2.0
>                 + data["y-velocity"]**2.0
>                 + data["z-velocity"]**2.0 )
> add_field("ThermalEnergy", function=_ThermalEnergy,
>          units=r"\rm{ergs}/\rm{cm^3}")
>
> def _convertEnergy(data):
>    return data.convert("x-velocity")**2.0
>
> def _GasEnergy(field, data):
>     return data["Gas_Energy"] / _convertEnergy(data)
> add_field("GasEnergy", function=_GasEnergy,
>           units=r"\rm{ergs}/\rm{g}", convert_function=_convertEnergy)
>
>
> def _TotalEnergy(field, data):
>    return data["Total_Energy"] / _convertEnergy(data)
> add_field("TotalEnergy", function=_TotalEnergy,
>          display_name = "\mathrm{Total}\/\mathrm{Energy}",
>          units=r"\rm{ergs}/\rm{g}", convert_function=_convertEnergy)
>
> and I switched back to the unstable branch. Still, I have a problem (that I
> noticed also other times): what I put in my_plugins.py is added to yt, but it
> does not override the existing definitions. In my case, I get again an error,
> because yt takes the definition of ThermalEnergy from
> yt-unstable/src/yt-hg/yt/frontends/enzo/fields.py , rather than from
> my_plugins.py (I can even copy the definitions in my yt script, but it
> doesn't change the problem). Is there a way to arrange my script in such a
> way to give priority to the definitions in my_plugins.py?
>
> Cheers,
>
>  Luigi
>
> On Monday 23 May 2011, Matthew Turk wrote:
>> Hi Luigi,
>>
>> Yes -- in the past we mutually aliased the fields "GasEnergy" and
>> "Gas_Energy" to each other, so that if one was not found the other was
>> looked for.  Unfortunately, this aliasing caused infinite recursion
>> loops:
>>
>> https://bitbucket.org/yt_analysis/yt/changeset/258083307f14
>>
>> so we had to remove this dual-aliasing.  I had hoped it wouldn't cause
>> problems; I tried very hard with Sam to come up with a way around
>> this, so that we could leave the aliasing in.  Unfortunately without
>> reworking the field container, we could not.  I am hoping that by the
>> end of the calendar year we will be able to rework the field container
>> to be more flexible.  However, for now, it should suffice to add into
>> your plugins file the lines that were removed in the linked commit.
>> This also took place while we standardized in Enzo on GasEnergy rather
>> than Gas_Energy (although I personally preferred the hyphen :):
>>
>> https://groups.google.com/d/topic/enzo-dev/64j9OZEAzcU/discussion
>>
>> Sorry for the inconvenience -- let me know if the plugins fix doesn't
>> work and we'll figure something else out.
>>
>> -Matt
>>
>> On Mon, May 23, 2011 at 3:49 PM,  <luigi at ita.uni-heidelberg.de> wrote:
>> > Dear all,
>> >
>> > I want to point out that, in the unstable branch, any attempt of using
>> > the field SoundSpeed returns an error. I have the impression that yt
>> > looks for GasEnergy, but in my dataset I have Gas_Energy defined. In the
>> > stable branch everything works well. I hope it does not depend on the
>> > data I'm analysing (some old Enzo 1.0 output)...
>> > Cheers,
>> >
>> >  Luigi
>
>
>
> --
>
> ---------------------------------------------------------------
>
> Luigi Iapichino
> Zentrum fuer Astronomie der Universitaet Heidelberg
> Institut fuer Theoretische Astrophysik
> Albert-Ueberle-Str. 2, D-69120 Heidelberg, Germany
> Tel: +49 6221 548983, Fax: +49 6221 544221
> e-mail: luigi at ita.uni-heidelberg.de
> URL: http://www.ita.uni-heidelberg.de/~luigi/
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