Installing VICE ¶

The simplest method to install VICE is to pull the source distribution from PyPI. To install the latest version, simply run

$ python -m pip install vice [--user]

from the command line. Users should add the --user flag if they do not have administrative privileges on their current machine; this will install VICE to their ~/.local directory.

Previous versions available on PyPI can be installed by simply specifying the version number:

$ python -m pip install vice==<version number> [...]

To speed up the installation process, users can tell pip to parallelize compiling VICE across some number of cores using the --global-option command. For example, to spread compilation across four cores:

$ python -m pip install vice --global-option="build" --global-option="-j4"

Invoking --global-option uses legacy behavior for pip and will generate warning messages to that effect. pip >= 24.0 will enforce the behavior change. Future versions of VICE will implement a more standard installation process; our developers are currently in the process of migrating VICE from the previously standard setup.py method to the new pyproject.toml standard introduced by PEP 517. In the meantime, if a parallelized installation is required, we ask that users simply downgrade (if necessary) to pip <= 24.0 and proceed accordingly.

Designed for systems with a Unix kernel, VICE does not function within a windows environment. Windows users should therefore install VICE within the Windows Subsystem for Linux (WSL). We emphasize that the Anaconda prompt provided for Windows is not a true Unix kernel, and therefore will fail to install and run VICE properly. As long as the call to pip is ran from within WSL, the proper pre-compiled binary for Linux systems provided on PyPI should install successfully. A manual installation on a windows machine must also be ran within WSL and cannot be conducted with the Anaconda prompt.

Although VICE can in principle be installed and ran on 32-bit hardware (e.g. i686 CPUs), we strongly discourage running VICE on such machines. Many of VICE’s unit tests, including those which run sanity checks on its calculations, fail on these machines.

Users who have or would like to modify VICE’s source code must conduct a manual installation. This also applies to users who would like to install a version of VICE that is still under development (these can be found on various branches of its GitHub repository) as well as for versions of python still under development.

Although it is generally not advisable to mix package managers, this is not a concern for VICE. We do not provide VICE distributions through conda, though users who typically install their python packages and manage their computing environments with conda can safely conduct their installation using pip. As noted below, VICE has no run-time dependencies, meaning that there is no environment that would need to be solved in the event the installation were conducted with conda.

If you have already installed VICE and would like help getting started, we recommend checking out VICE’s tutorial. Further usage guidelines can be found here.

Dependencies ¶

VICE has no primary run-time dependencies; that is, it does not require any external software to run properly. All that is required to run VICE is python itself. There are however a handful of features which are enabled when certain dependencies are satisfied, and we recommend users install them to make use of VICE to its full extent. These secondary dependencies are as follows:

dill >= 0.2.0
dill allows VICE to save python functions with its output. This makes it possible to reconstruct simulations from their output.
matplotlib >= 2.0.0
matplotlib is necessary for the show function of the output object. This is intended to allow users to visually inspect the results of their simulations in ipython, a jupyter notebook, or something similar without having to plot it themselves. This is included purely for convenience, and is not intended to produce publication-quality figures.
NumPy
VICE’s tutorial and example code often make use of NumPy, but the user does not need NumPy to use VICE.

A Note on Implementation ¶

VICE is implemented in ANSI/ISO C and is wrapped using only standard library Python and Cython. It is thus independent of the user’s version of Anaconda (or lackthereof). It is NumPy- and pandas-compatible, but neither NumPy- nor pandas-dependent. That is, it will recognize user input from both NumPy and pandas data types such as the NumPy array or the pandas dataframe, but is designed to run independently of them.

Manual Installation ¶

Users who have modified VICE’s source code must compile and install their updated version manually. Otherwise, we recommend simply making use of pip as described above. If you have already modified VICE’s source code or plan to do so, we encourage you to reach out to one of our developers - we’d be happy to consult with you to help VICE meet your needs!

Though VICE does not have any run-time dependencies, there are a few compile-time dependencies that must be satisfied to install from source. They are as follows:

Python >= 3.8
setuptools >= 18.0
gcc >= 4.6 or clang >= 3.6

On Mac OS X and Linux architectures, it is likely that one of gcc or clang come pre-installed. Users may install with alternative C compilers if they so choose, but VICE is tested with only gcc and clang. While a sizable portion of VICE’s source code is written in Cython and requires Cython >= 3.0 to compile, this should be handled automatically by setuptools. Nonetheless, it is trivial to install it manually via python -m pip install Cython>=3.0.

Once the build dependencies are satisfied, download the source code using a terminal and change directories into the source tree:

$ git clone https://github.com/giganano/VICE.git
$ cd VICE

From here, users may change to a specific branch if necessary. For example, VICE’s latest development version is on a branch named development, and git checkout development will take you there. To then compile and install VICE, simply run:

$ python -m pip install .

Users who do not have administrator’s privileges on the system they’re conducting the installation should add the --user command-line argument, which will conduct a local installation. A parallelized build using the --global-option legacy behavior as described above is also available when installing manually.

Following the installation, if desired, VICE’s unit tests can be run with

$ make tests

This can also be achieved from within python itself:

import vice
vice.test()

If you have issues installing or running VICE, please see the section on Troubleshooting Your Build. If your installation was successful and you would like help getting started, usage guidelines can be found here.

Things to Avoid ¶

Parallelization with the gcc compiler
Users manually installing VICE with the gcc C compiler should avoid parallelized installations with pip’s --global-option legacy behavior. In practice, the developer’s find that gcc is not able to successfully complete compiling VICE across multiple cores. This should be a non-issue for those running Mac OS, as gcc must be installed and clang is the default compiler. For those on Linux, however, gcc is the default.

Simultaneous installations
Users manually installing VICE from source for multiple versions of python should not run the setup.py file in separate terminals simultaneously; this will cause one of the builds to fail as they will attempt to write to files of the same name. Likewise, users should not run the tests for multiple versions of python simultaneously; this will almost certainly cause a segmentation fault.

Troubleshooting Your Build ¶

The following are a number of issues that can arise when manually installing VICE. If none of these options solve your problem, or if you attempted an installation with pip as opposed to installing manually, please open an issue here.

Running the setup.py File Failed ¶

Did you attempt your installation on Windows without using WSL? If not, did you attempt the installation for multiple versions of python simultaneously? Alternatively, did you run a parallelized installation using the gcc C compiler? If none of these solutions apply to your case, please open an issue here.

Running the Tests Resulted in a Segmentation Fault ¶

Did you run the tests for multiple versions of python simultaneously? If not, please open an issue here.

VICE Isn’t Running from the Command Line ¶

If vice doesn’t run from the terminal after installing, first check that python3 -m vice runs; the two have the same functionality. If neither work, then it’s likely there was an issue with the installation, and we recommend rerunning the install process, making sure that the instructions are followed as closely as possible. If this still does not work, please open an issue here.

If python3 -m vice works, but vice does not, then it’s likely that that command line entry was copied to a directory not on your PATH. The simplest patch for this issue is to create an alias for vice mapping it to the longer command. This can be done by adding the following line to your ~/.bash_profile:

alias vice="python3 -m vice"

Then either run source ~/.bash_profile or restart your terminal for the alias to take effect.

Alternatively, the proper file can simply be copied to any given directory in your computer. If this directory is not on your PATH, then your PATH must be modified to contain this file’s new location. For example:

$ cp ./bin/vice ~/.local/bin

This will place the command line entry in the ~/.local/bin/ directory, which can be permanently added to your path by adding

export PATH=$HOME/.local/bin:$PATH

to your ~/.bash_profile. As with the alias solution, this will require either running source ~/.bash_profile or restarting your terminal to take effect.

Note: If you have installed VICE with the --user option, it is likely that VICE has automatically made the above modification to your PATH, and that either running source ~/.bash_profile or restarting your terminal is all that is required after copying the file to ~/.local/bin. If you have copied the file to a different directory, VICE will not have added that file to your PATH.

More information on modifying your PATH can be found here.

If this does not fix the issue, please open an issue here.

Compiler Failure ¶

This is usually an indication that the build should not be ran on multiple cores, which is usually the case with the gcc C compiler. If you’re installing VICE with pip, simply restart the process without invoking a parallelized installation. If you’re installing manually from source, first run make clean, and then restart the process outlined above.

If compiler failures persist, please open an issue here.

Uninstalling VICE ¶

If you have installed VICE from PyPI, it can be uninstalled from the terminal via pip uninstall vice. When prompted, simply confirm that you would like the files removed. If you have downloaded VICE’s supplementary data for use with the milkyway object, it is recommended that you remove these files first by running

import vice
vice.toolkit.hydrodisk.data._h277_remove()

before the pip uninstall vice command.

If you have installed from source, it is likely that pip uninstall vice can still achieve the same effect. Uninstalling manually requires a couple of steps. First, you must identify the path to the directory that it was installed to. This can be done by launching python and running the following two lines:

import vice
print(vice.__path__)

Note that there are four underscores in total: two each before and after path. This will print a single-element list containing a string denoting the name of the directory holding VICE’s compiled extensions, of the format /path/to/install/dir/vice. Change into this directory, and remove the VICE tree:

$ cd /path/to/install/dir/
$ rm -rf vice/

Then, check the remaining contents for an egg. This will likely be of the format vice-<version number>.egg-info. Remove this directory as well:

$ rm -rf vice-<version number>.egg-info

Finally, the command line entry must be removed. The full path to this script can be found with the which command in the terminal:

$ which vice

This will print the full path in the format /path/to/cmdline/entry/vice. Pass it to the rm command as well:

$ rm -f /path/to/cmdline/entry/vice

If this process completed without any errors, then VICE was successfully uninstalled. To double-check, rerunning which vice should now print nothing, and attempting to import VICE into python should result in a ModuleNotFoundError.