Over the last few weeks, Matt Turk, Christopher Moody, and Stephen Skory have been working to improve the integration of the Rockstar halo finder in yt. Rockstar was written primarily by Peter Behroozi and has a main website here. Linked there is the source and the most current edition of the method paper which includes a timing and scaling study.
Rockstar is a six dimensional halo finder, meaning that it considers both particle position and momentum when locating dark matter halos.
This is a long blog post! The short of it is:
If you’re using Enzo or FLASH, you can probably do most of what you want to do with 3.0. But there are probably bugs, and you can’t volume render yet. But every bug or missing feature you find is a useful piece of information that can help speed up development. If you’re using RAMSES, 3.0 will be a vast improvement!
Grid refinement In yt, you can now generate very simple initial conditions:
from yt.mods import * from yt.frontends.stream.api import load_uniform_grid from yt.frontends.gdf.api import * from yt.utilities.grid_data_format.writer import write_to_gdf class DataModifier(object): pass class TophatSphere(DataModifier): def __init__(self, fields, radius, center): self.fields = fields self.radius = radius self.center = center def apply(self, grid, container): r = ((grid['x'] - self.center)**2.0 + (grid['y'] - self.center)**2.0 + (grid['z'] - self.center)**2.0)**0.5 for field in self.
We’re proud to announce the release of version 2.4 of the yt Project, http://yt-project.org/ . The new version includes many new features, refinements of existing features and numerous bugfixes. We encourage all users to upgrade to take advantage of the changes.
yt is a community-developed analysis and visualization toolkit, primarily directed at astrophysical hydrodynamics simulations. It provides full support for output from the Enzo, FLASH, Orion, and Nyx codes, with preliminary support for several others.
Tomorrow we’re going to try something new – Google Hangouts! If you’d like help with something, to share some feedback, or just to say hi to other community members, stop by Tuesday, May 1st. We’ll be starting up around 2PM Eastern and continuing for a couple hours.
If this works out, we’ll try it again from time to time, to catch up on new developments, help out with scripts or visualization issues, soliciting feedback, and to chat about using and developing yt.
Now that the post-workshop preparations and work have settled down, I thought it might be interesting to share some of the developments going on with yt. We’re still a long way from a new release, so these interim ‘development’ updates are meant to be a bit of a teaser. As always, these features are either in the main branch or (if noted) in a public fork on BitBucket. If they sound interesting, drop us a line on `yt-dev <http://lists.
The yt workshop last week in Chicago ( http://yt-project.org/workshop2012/ ) was an enormous success. On behalf of the organizing and technical committees, I’d like to specifically thank the FLASH Center, particularly Don Lamb, Mila Kuntu, Carrie Eder, for their hospitality; the venue was outstanding and their hospitality touching. Additionally, we’re very grateful to the Adler Planetarium’s Doug Roberts and Mark SubbaRao for hosting us on Wednesday evening – seeing the planetarium show as well as volume renderings made by yt users up on the dome was so much fun.
The first yt workshop is in just about a week. We’ve updated the website with the current list of talks, along with information about getting to and from the workshop from the conference hotel, and information about how to get the sample data. Keep your eyes on the website in the lead up to the workshop, as we’ll be posting a script for fisheye lens renderings for our viz night at the Adler, information about the talks and example scripts, and other useful info.
Just in time for the New Year, we’re happy to announce the release of yt version 2.3! ( http://yt-project.org/ ) The new version includes many new modules and enhancements, and the usual set of bug fixes over the last point release. We encourage all users to upgrade to take advantage of the changes.
yt is a community-developed analysis and visualization toolkit for astrophysical simulation data. yt provides full support for Enzo, Orion, Nyx, and FLASH codes, with preliminary support for the RAMSES code (and a handful of others.
A useful new addition to yt are boolean data containers. These are hybrid data containers that are built by relating already-defined data containers with each other using boolean operators. Nested boolean logic, using parentheses, is also supported. The boolean data container (or volume) is made by constructing a list of volumes interspersed with operators given as strings. Below are some examples of what can be done with boolean data containers.
yt now has a Google Plus page. Here’s we’ll post smaller, less blog-worthy items, hold video conferencing ‘hangouts’, and so on. Encircle away! And if you post something you’d like to be reshared, just be sure to explicitly share it with ‘+yt’ so we know.
A few of us worked this past week on a couple yt projects and made what we think is significant progress. Two of the items we focused on were testing and parallelism.
For testing, we’ve broadened the test suite to include many more functions and derived quantities. We now have 548 tests that include (off and on-axis) slices, (off and on- axis) projections, phase distributions, halo finding, volume rendering, and geometrical region cuts such as rectangular solids, spheres, and disks.
I’m pleased to announce the 2012 yt Workshop at the FLASH Center in Chicago, January 24-26.
The workshop will be aimed at both users and developers of yt. We will begin with intensive user training, moving from basic usage to advanced and parallel usage. Users are encouraged to bring their ideas and prototypes for new analysis routines as there will be opportunities to work with more experienced developers. We will then address to how to modify, extend and contribute to yt, and transition to a developers workshop.
yt has many extension packages to help you in your scientific workflow! Check
these out, or create your own.
ytini is set of tools and tutorials for using yt as a tool inside the 3D visual
effects software Houdini or a data pre-processor externally to Houdini.
Trident is a full-featured tool that projects arbitrary sightlines through
astrophysical hydrodynamics simulations for generating mock spectral
observations of the IGM and CGM.
pyXSIM is a Python package for simulating X-ray observations from astrophysical
Analyze merger tree data from multiple sources. It’s yt for merger trees!
yt_idv is a package for interactive volume rendering with yt!
It provides interactive visualization using OpenGL for datasets
loaded in yt. It is written to provide both scripting and interactive access.
widgyts is a jupyter widgets extension for yt,
backed by rust/webassembly to allow for browser-based, interactive exploration
of data from yt.
We welcome contributions from all members of the yt community. Feel free to
reach out if you need any help.
the yt data hub
The yt hub at https://girder.hub.yt/ has a ton of resources to check out,
whether you have yt installed or not.
The collections host all sorts of data
that can be loaded with yt. Some have been used in publications, and others are
used as sample frontend data for yt. Maybe there’s data from your simulation
The rafts host the yt quickstart notebooks,
where you can interact with yt in the browser, without needing to install it
locally. Check out some of the other rafts too, like the widgyts release
notebooks – a demo of the widgyts yt extension pacakge; or the notebooks from
the CCA workshop – a user’s workshop on using yt.