I am pleased to announce the release of ytree version 1.1.
ytree is a merger-tree code with yt-like syntax for loading data and
accessing fields. ytree can:
* return tree and halo data fields with symbolic units like in yt
* create merger-trees for Gadget FoF/Subfind catalogs
* load merger-trees from Rockstar halo catalogs and consistent-trees
* save individual and collections of merger-trees into a reloadable
As of ytree version 1.1, field access is even more yt-like.
>>> import ytree
>>> a = ytree.load("tree_0_0_0.dat") # consistent-trees
>>> # masses for roots of all trees
>>> print (a["mvir"].to("Msun"))
[ 1.65035971e+13, 1.43309353e+13, 5.18129496e+14, ...
3.47482014e+12, 1.30273381e+12, 3.47482014e+12] Msun
>>> # mass for the root of the first tree
>>> print (a["mvir"])
>>> # most massive progenitors for first tree
>>> print (a["line", "mvir"])
[ 1.14700000e+13, 1.20700000e+13, 1.23700000e+13, ...
3.32000000e+12, 1.20700000e+12, 2.71600000e+12] Msun/h
ytree is compatible with both Python 2 and 3 and can be installed with
pip install ytree
For more information, please visit:
ytree is an open-source project. If you're interested in
contributing, please do!
our cloud provider "will have a brief network outage starting at 10AM
(CST/UTC-6) on Friday, January 13th in order to upgrade its network
hardware. The upgrade will install new hardware and software and will
double the bandwidth.
Before the outage the new hardware will already be configured and
connected to the network so the interruption should be brief, hopefully
about 5 minutes."
This affects: hub (only running notebooks), jenkins, blog, pastebin,
slackbots (yt-fido, irc bridge).
In theory it should go unnoticed. On the other hand, what could possibly
go wrong on Friday 13th...?
In the following cookbook example:
the variance along the profile is extracted:
variance = prof.variance['gas', 'velocity_magnitude'].value
but is then labelled as the standard deviation when the plot is created:
plt.loglog(radius, variance, label='Standard Deviation')
So, does "prof.variance" return the standard deviation and not the
variance? Or, is the plot mislabelled? Should the plot instead be:
plt.loglog(radius, np.sqrt(variance), label='Standard Deviation')
I have one simple question, but it bothers me these days.
I used the yt to analysis the "hdf5" files, which generated by Gadget-2.
These files have basic fields, like: ("PartType0", "*"), ("PartType1",
"*") and ("all", "*"). Then I want to plot the density map and
temperature map, it seems need some derived fields, like: ("gas",
"density") and ("gas", "temperature").
I'm curious about how the ("gas","temperature") was derived, so I
browsed a lots of documents on the Web, but found nothing. Please see
About the field of ('gas','temperature'), there is "No source
available" in "Field Source"!
In my data, the field ("PartType0","InternalEnergy") is provided by me,
and I think the temperature should calculated by Internal Energy "E"
with the function: k*T = (Gamma -1)*µ*mp*E, where k = 1.38E-16 erg/K is
Boltzmann constant, Gamma = 5/3 for adiabat particles, μ = 0.6 is the
corresponding mean molecular weight, and mp = 1.67E-24 g is proton mass.
But this result is about half of the value of ("gas","temperature").
So what you may know is why, which one is right? I need your help!
Thank you a lot, and happy new year!
Department of Physics, Shanghai Jiao Tong University
800 Dongchuan Road, Minhang, Shanghai 200240, PRC
E-mail : hudan_bazhaoyu(a)163.com <mailto:firstname.lastname@example.org>
I'm working on a project where I'm comparing different RAMSES simulations.
However I'm running into a problem with memory.
It seems that yt loads the whole simulation into memory even though I'm
only interested in a number of dark matter halos which I have the
It also seems like it doesn't drop the first simulation out of memory when
I'm done making the figures I want for that one.
This quickly fills up the memory.
You can find the relevant parts of my code at the pastebin at
I'm running yt version 3.3.2
What am I doing wrong?
Also, is there a way to change the axis names?
I'm making some dark matter density profiles using the
('deposit','io_density') field and this gives IO Density on the y axis, but
I just want it to say Dark matter density so my readers actually understand
what I'm talking about.
Thanks for helping