Follow these steps to successfully install Trident and its dependencies.

Versions of Trident

Currently, there are two versions of Trident: the stable version, and the developent version. The stable version is tried, and tested, and it operates on a stable version of yt. The development version is actively being updated with new features, and it is also tied to the development version of yt, so occasionally unforseen bugs can crop up as these new features are added. The installation steps are slightly different between the two versions, in that installing stable is easier and faster than dev, so pay attention in the steps below. Don’t worry if you want to change later, you can always switch between the two versions easily enough by following the directions in Uninstallation or Switching Code Versions.

Step 1: Install yt

yt is a python-based software package for the analysis and visualization of a variety of different datasets, including astrophysical hydrodynamical data. yt is a dependency of Trident, so you must install it before Trident will work. There are several methods for installing yt, which are all discussed in detail in the yt installation documentation.

Installing yt for the Stable Release

The stable release of Trident runs off of the latest stable release of yt. You can install yt by following any of the methods on its installation page, but we find that the easiest is to use the all-in-one install script:

$ wget
$ bash

If you already have conda installed, it’s even faster and easier:

$ conda install -c conda-forge yt

Finally, if you already have the development version of yt, you can skip the above steps and just update to the stable version:

$ cd <path/to/yt/repo>
$ hg up stable

Installing yt for the Development Version

The development version of Trident runs off of the development version of yt, since much of the functionality is co-developed between the two packages. You can install yt by following any of the methods on its installation page, but we find that the easiest is to use the all-in-one install script and build from source (i.e. with settings INST_CONDA=1 and INST_YT_SOURCE=1):

$ wget
$ ... edit the to mark INST_YT_SOURCE=1 ...
$ bash

Alternatively, if you already have conda installed, you can get the most recent nightly build of the development version of yt with:

$ conda install -c yt

Step 2: Install Trident

Installing the Stable Release

You can install the most recent stable release of Trident using pip:

$ pip install trident

Installing the Development Version

To get the development version, you’ll pull the source code from its repository using mercurial, which should be installed as part of your yt installation. After that, you’ll use pip to install the source directly. Go to your desired source code installation directory and run:

$ hg clone
$ cd trident
$ pip install -e .

Step 3: Get Ionization Table and Verify Installation

In order to calculate the ionization fractions for various ions from density, temperature, metallicity fields, you will need an ionization table datafile and a configuration file. Because this datafile can be large, it is not packaged with the main source code. The first time you try to do anything that requires it, Trident will attempt to automatically set this all up for you with a series of interactive prompts. This step requires an internet connection the first time you run it.

In addition, Trident provides a simple test function to verify that your install is functioning correctly. This function not only tries to set up your configuration and download your ion table file, but it will create a simple one-zone dataset, generate a ray through it, and create a spectrum from that ray. This should execute very quickly, and if it succeeds it demonstrates that your installation has been totally successful:

$ python
>>> import trident
>>> trident.verify()
...Series of Interactive Prompts...

If you cannot directly access the internet on this computer, or you lack write access to your $HOME directory, or this step fails for any reason, please follow our documentation on Manually Installing your Ionization Table.

Step 4: Science!

Congratulations, you’re now ready to use Trident! Please refer to the documentation for how to use it with your data or with one of our sample datasets. Because Trident is in beta, the docs are not complete, and the API may still change in slight ways. Please join our mailing list for announcements about when the code is officially released.

Manually Installing your Ionization Table

If for some reason you are unable to install the config file and ionization table data automatically, you must set it up manually. When Trident runs, it looks for a configuration file called config.tri in the $HOME/.trident directory or alternatively in the current working directory (for users lacking write access to their $HOME directories). This configuration file is simple in that it tells Trident a few things about your install including the location and filename of your desired ionization table. Manually create a text file called config.tri with contents following the form:

ion_table_dir = ~/.trident
ion_table_file = hm2012_hr.h5

To manually obtain an ion table datafile, download and gunzip one from: . While the config.tri file needs to exist in your $HOME/.trident directory or in the working directory when you import trident, the ion_table datafile can exist anywhere on the file system. Just assure that the config file points to the proper location and filename of the ion table datafile.

Now, to confirm everything is working properly, verify your installation following Step 3: Get Ionization Table and Verify Installation. If this fails or you have additional problems, please contact our mailing list.

Uninstallation or Switching Code Versions

Uninstallation of the Trident source code is easy. If you installed the stable version of the code via pip, just run:

$ pip uninstall trident

If you installed the dev version of Trident, you’ll have to delete the source as well:

$ pip uninstall trident
$ rm -rf </path/to/trident/repo>

If you want to switch between the two stable and development versions, just uninstall your version of the code as above, and then install the desired version as described in Step 2: Install Trident

To fully remove the code from your system, remember to remove any ion table datafiles you may have downloaded in your $HOME/.trident directory, and follow the instructions for how to uninstall yt.

Updating to the Latest Version

If you want more recent features, you should periodically update your Trident codebase.

Updating to the Latest Stable Release

If you installed the “stable” version of the code using pip, then you can easily update your trident and yt installations:

$ pip install -U trident
$ yt update

Updating to the Latest Development Version

If you installed the “development” version of the code, it’s slightly more involved:

$ cd <path/to/trident/repo>
$ hg pull
$ hg up
$ pip install -e .
$ yt update

For more information on updating your yt installation, see the yt update instructions.