[yt-users] more gadget visualization

[Desika Narayanan]

Hey Matt,

This worked perfectly - thanks a lot!
-d


On Wed, Nov 27, 2013 at 12:28 PM, Matthew Turk <matthewturk at gmail.com>wrote:

> Hi Desika,
>
> On Wed, Nov 27, 2013 at 11:56 AM, Desika Narayanan
> <dnarayan at haverford.edu> wrote:
> > Hey Team YT,
> >
> > I have a couple of (I think super-easy) questions:
> >
> > a. How do you paste a script to the yt pastebin?  I've done it
> successfully
> > once before, but can't for the life of me figure out how I did it.
> >
>
> :)  You can use the command "yt pastebin" and then the script name.
> There's also "yt pastebin_grab" which takes a number and spits out the
> corresponding script to stdout.
>
> > b. Relatedly, there's a (like 10 line) script appended below where I
> > projection plot gas densities from a Gadget simulation.    I'd like to be
> > able to do the following:
> >
> >     b.i - I'd like to be able to project other fields.  For example, if I
> > look at pf.h.field_list, I get that for particle type 0, the fields:
> > ('PartType0', 'Masses'), ('PartType0', 'Metallicity') exist.  However,
> if I
> > try to project:
> >
> >>p = ProjectionPlot(pf,'z',(("deposit", "PartType0_metallicity")))
> >
> > (instead of the successful density line below), I get the error :
> >
> >>YTFieldNotFound: Could not find field '('deposit',
> >> 'PartType0_metallicity')' in snapshot_006.
> >
> >
> >     b.ii.  Assuming the parts from b.i are possible, is it then possible
> to
> > multiply two fields together in the projection (say, I wanted metal mass
> and
> > wanted to multiply the particle masses by the particle metallicities).
> > Similarly, is it possible to multiply a field by a constant for the
> particle
> > deposition into a projection plot?
> >
>
> So!  Here's one place we have not really pushed the limits of our
> field deposition functionality.  As it stands, we only have a very
> limited taxonomy of fields that are pre-defined, but it's possible to
> define your own.  I think ultimately we'll want to actually create
> *smoothing* fields for these, rather than the "deposit" functionality
> that's in there now, but that's in an open PR at the moment.  Once the
> actual SPH smoothing is in the code (and it just needs the
> normalization stuff you and I talked about a while back, but my supply
> of round tuits has been a bit low this week) we'll generate these
> automatically for all the fields associated with gas particles and
> they'll just be available.
>
> For now, to do what you're describing, you can define your own field like
> so:
>
> @derived_field(name=("deposit", "PartType0_metallicity"),
> validators=[ValidateSpatial()])
> def _my_field(field, data):
>         pos = data["PartType0", "Coordinates"]
>         d = data.deposit(pos, [data["PartType0", "Metallicity"]],
> method = "sum")
>         d /= data["gas","CellVolume"]
>         return d
>
> There are other options you can supply, but here's what it will do: it
> will sum the values of Metallicity in each cell, then divide by the
> volume of the cell, giving an average.  You can apply multiplications
> of mass and whatnot, divisions of total deposited mass, and on and on,
> all based on the prescription just there.
>
> Let me know if that helps,
>
> Matt
>
> >
> > Thanks,
> > Desika
> >
> >
> > -------------------------
> > from yt.mods import *
> >
> >
> > snap = "/Users/desika/powderday/grid_data/snapshot_006.hdf5"
> > bbox = [[-220.0, 220.0],
> >         [-220.0, 220.0],
> >         [-220.0, 220.0]]
> >
> >
> > unit_base = {'UnitLength_in_cm'         : 3.08568e+21,
> >              'UnitMass_in_g'            :   1.989e+43,
> >              'UnitVelocity_in_cm_per_s' :      100000}
> >
> > pf = load(snap,unit_base = unit_base,bounding_box=bbox)
> > pf.h
> >
> > p = ProjectionPlot(pf,'z',(("deposit", "PartType0_density")))
> > p.set_width(200,'kpc')
> > p.save()
> >
> >
> > _______________________________________________
> > 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/20131127/5a7cbfdf/attachment.html>