## Version & Installation¶

### How can I tell what version of yt I’m using?¶

If you run into problems with yt and you’re writing to the mailing list or contacting developers on IRC, they will likely want to know what version of yt you’re using. Oftentimes, you’ll want to know both the yt version, as well as the last changeset that was comitted to the branch you’re using. To reveal this, go to a command line and type:

pip install -e .




### yt seems to be plotting from old data¶

yt does check the time stamp of the simulation so that if you overwrite your data outputs, the new set will be read in fresh by yt. However, if you have problems or the yt output seems to be in someway corrupted, try deleting the .yt and .harray files from inside your data directory. If this proves to be a persistent problem add the line:

from yt.config import ytcfg; ytcfg["yt","serialize"] = "False"


to the very top of your yt script. Turning off serialization is the default behavior in yt-3.0.

### How can I change yt’s log level?¶

yt’s default log level is INFO. However, you may want less voluminous logging, especially if you are in an IPython notebook or running a long or parallel script. On the other hand, you may want it to output a lot more, since you can’t figure out exactly what’s going wrong, and you want to output some debugging information. The yt log level can be changed using the The Configuration File, either by setting it in the $HOME/.config/yt/ytrc file: $ yt config set yt loglevel 10  # This sets the log level to "DEBUG"


which would produce debug (as well as info, warning, and error) messages, or at runtime:

from yt.funcs import mylog
mylog.setLevel(40) # This sets the log level to "ERROR"


which in this case would suppress everything below error messages. For reference, the numerical values corresponding to different log levels are:

Level

Numeric Value

CRITICAL

50

ERROR

40

WARNING

30

INFO

20

DEBUG

10

NOTSET

0

### Can I always load custom data objects, fields, quantities, and colormaps with every dataset?¶

The The Plugin File provides a means for always running custom code whenever yt is loaded up. This custom code can be new data objects, or fields, or colormaps, which will then be accessible in any future session without having modified the source code directly. See the description in The Plugin File for more details.

### How do I cite yt?¶

If you use yt in a publication, we’d very much appreciate a citation! You should feel free to cite the ApJS paper with the following BibTeX entry:

@ARTICLE{2011ApJS..192....9T,
author = {{Turk}, M.~J. and {Smith}, B.~D. and {Oishi}, J.~S. and {Skory}, S. and
{Skillman}, S.~W. and {Abel}, T. and {Norman}, M.~L.},
title = "{yt: A Multi-code Analysis Toolkit for Astrophysical Simulation Data}",
journal = {The Astrophysical Journal Supplement Series},
archivePrefix = "arXiv",
eprint = {1011.3514},
primaryClass = "astro-ph.IM",
keywords = {cosmology: theory, methods: data analysis, methods: numerical },
year = 2011,
month = jan,
volume = 192,
eid = {9},
pages = {9},
doi = {10.1088/0067-0049/192/1/9},