[yt-users] Fortran kD Tree Setup and Clumps

[Matthew Turk]

Hi Francia,

I'm sorry to hear that you're still having trouble with this.

On Thu, Aug 30, 2012 at 12:38 PM, Francia F. Riesco <ff2214 at columbia.edu> wrote:
>   Everybody good afternoon,
>     about Fortran kD Tree Setup, just to keep thread with my fix.
>     1) I downloaded the YT-DEV version and it didn't fix my problem.
>     However, when I downloaded Forthon-0.8.7.tgz it did the trick.

Stephen, Geoffrey -- what's the summary of why this is still a
problem?  If we know that Forthon-0.8.7 fixes the issue, why can't we
just revert to that in the install script?

>
>     2) Now I want to talk about another issue that I am getting. This time
>     is with clumps. I am using an enzo data, with the code example in the
>     YT documentation. this is my code:
>
[snip]
>     I did it with the whole data (it took forever), however, I got the
>     same exactly error. Anybody has an advice??

I think I've figured out what's going on.  This data was generated
with a version of Enzo that diverged from main development before
field names had been standardized, and while it contains
"Total_Energy" it does not contain "TotalEnergy" which is what fields
are now referred to as.  (It also must have been done using the Zeus
hydro solver.)  So it's a perfect storm for yt not being sure how to
get the thermal energy back, which is where this is all coming from --
the clump finder (as opposed to the level set identifier) only returns
gravitationally bound clumps.

The fix for this is to alias Total_Energy to TotalEnergy, so that when
the latter is requested, the former is returned.  I have now done this
in the development repository.  You can update your installation by
running:

yt update

You can test that this will work (without running the full clump
finder) by using a command like this:

dd = pf.h.sphere("c", 100.0/pf['kpc'])
print dd.quantities["Extrema"]("ThermalEnergy")

Please do let us know if this fixes the issue.

Best,

Matt