Hi Kacper, Matt, Yes, that fixes the problem, although I am rather confused as to why. The nuclei density fields depend on the species fields, so I would have thought that the species fields need to be added first. Can someone explain what is happening here? Britton On Thu, Oct 2, 2014 at 9:10 AM, Kacper Kowalik wrote:

On Thu, Oct 2, 2014 at 9:03 AM, Matthew Turk wrote:

...

Hi Britton,

On Thu, Oct 2, 2014 at 8:34 AM, Britton Smith wrote:

...

Hi all,

There seems to be an issue accessing the nuclei density fields. These are derived fields that give the total number density of an element with names like "H_nuclei_density." At some point, these have stopped working and I am trying to debug this. To reproduce this, one can do the following: ds = yt.load("enzo_cosmology_plus/DD0046/DD0046") ad = ds.all_data() ad["H_nuclei_density"]

I have traced this as far as the following. In the call to create_field_info, a YTFieldNotFound exception is raised on line 137 of yt/fields/species_fields.py. Here, the nuclei density field function is trying to access a number density field that should exist, but doesn't seem to at the moment. Later on it does, but not at this moment. Does anyone have any advice for where to look next?

It might have to do with the order of field addition. When does the field actually get added? Can you insert pdb calls into add_field whenever the field you're looking for is added, and see when it occurs compared to when the other one does?

Hi Britton, it's just as Matt suggested. Creating nuclei fields prior to species fields fixes the issue:

http://paste.yt-project.org/show/5143/

Cheers, Kacper

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Hi all, Kacper and Matt were correct. The nuclei density fields were getting created before their dependencies. The issue was that the add_nuclei_density_fields call needed to be moved into the species fields plugin. I've issued a PR to fix this. Thanks for your help. Britton On Thu, Oct 2, 2014 at 2:42 PM, Kacper Kowalik wrote:

On Thu, Oct 2, 2014 at 12:37 PM, Britton Smith wrote:

...

Hi Kacper, Matt,

Yes, that fixes the problem, although I am rather confused as to why. The nuclei density fields depend on the species fields, so I would have thought that the species fields need to be added first. Can someone explain what is happening here?

If species list is empty (calling add_nuclei_dens... will do that), there's a fallback that adds ["H", "He"] at yt/fields/species_fields.py:123. I should be clear that what I've suggested was merly a workaround.

Cheers, Kacper

...

Britton

On Thu, Oct 2, 2014 at 9:10 AM, Kacper Kowalik wrote:

...

On Thu, Oct 2, 2014 at 9:03 AM, Matthew Turk wrote:

...

Hi Britton,

On Thu, Oct 2, 2014 at 8:34 AM, Britton Smith wrote:

...

Hi all,

There seems to be an issue accessing the nuclei density fields. These are derived fields that give the total number density of an element with names like "H_nuclei_density." At some point, these have stopped working and I am trying to debug this. To reproduce this, one can do the following: ds = yt.load("enzo_cosmology_plus/DD0046/DD0046") ad = ds.all_data() ad["H_nuclei_density"]

I have traced this as far as the following. In the call to create_field_info, a YTFieldNotFound exception is raised on line 137 of yt/fields/species_fields.py. Here, the nuclei density field function is trying to access a number density field that should exist, but doesn't seem to at the moment. Later on it does, but not at this moment. Does anyone have any advice for where to look next?

It might have to do with the order of field addition. When does the field actually get added? Can you insert pdb calls into add_field whenever the field you're looking for is added, and see when it occurs compared to when the other one does?

Hi Britton, it's just as Matt suggested. Creating nuclei fields prior to species fields fixes the issue:

http://paste.yt-project.org/show/5143/

Cheers, Kacper

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_______________________________________________ yt-dev mailing list yt-dev@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-dev-spacepope.org

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