************
Installation
************
Requirements
============
cysgp4 has the following strict requirements:
- `Python `_ 3.5 or later
- `setuptools `_: Used for the
package installation.
- `NumPy `_ 1.13 or later
Installing cysgp4
==================
Using Anaconda
--------------
The easiest way to install `~cysgp4` is certainly to make use of the
great `Anaconda Python distribution `_:
.. code-block:: bash
conda install cysgp4 -c conda-forge
Using pip
-------------
To install cysgp4 with `pip `_,
simply run
.. code-block:: bash
pip install cysgp4
.. note::
You may need a C++ compiler (e.g., ``g++``) with OpenMP support to be
installed for the installation to succeed, if no `binary wheel
`_ is available for your OS and Python version
on the `Python Package Index `_
.. note::
Use the ``--no-deps`` flag if you already have dependency packages
installed, since otherwise pip will sometimes try to "help" you
by upgrading your installation, which may not always be desired.
.. note::
If you get a ``PermissionError`` this means that you do not have the
required administrative access to install new packages to your Python
installation. In this case you may consider using the ``--user`` option
to install the package into your home directory. You can read more
about how to do this in the `pip documentation
`_.
We recommend to use a Python distribution, such as `Anaconda
`_, especially, if you are on
:ref:`windows_install`.
Do **not** install cysgp4 or other third-party packages using ``sudo``
unless you are fully aware of the risks.
.. _source_install:
Installation from source
------------------------
There are two options, if you want to build cysgp4 from sources. Either, you
install the tar-ball (`*.tar.gz` file) from `PyPI
`_ and extract it to the directory of
your choice, or, if you always want to stay up-to-date, clone the git
repository:
.. code-block:: bash
git clone https://github.com/bwinkel/cysgp4
Then go into the cysgp4 source directory and run:
.. code-block:: bash
pip install .
Again, consider the ``--user`` option or even better use `virtualenv
`_ or a Python distribution
such as `Anaconda `_ to avoid messing up
the system-wide Python installation.
.. _windows_install:
Installation on Windows
-----------------------
Note that for Windows machines we provide a binary wheel (Python 3.5+ only)
via `PyPI`_ and installation is as easy as with Linux:
.. code-block:: bash
pip install cysgp4
.. note::
If you are desperate, you can install cysgp4 from source even on Windows.
You'll need to install a suitable C++-compiler; `see here
`_. The cysgp4
package needs Python 3.5 or later, which means VC++ Version 14 is
mandatory. The easiest way to obtain it, is by installing the
`Visual C++ 2015 Build Tools
`_ which is
"only" 4 GBytes large...
.. _macos_install:
Installation on MacOS
---------------------
Installation on MacOS can be a bit tricky, because the standard C++ compiler
does not support OpenMP. We provide wheels on PyPI, such that you can
.. code-block:: bash
pip install cysgp4
however, you need to have the GCC C++ compiler (see below), otherwise you'll
likely get some error message.
Also, if you want to install from source, you must have a C++ compiler. There
are basically two options, using the gcc suite (recommended) or clang/LLVM.
gcc
~~~
.. code-block:: bash
brew install gcc
brew link --overwrite gcc
You may have to set build-related environment variables to point towards the
gcc compilers instead of the standard clang:
.. code-block:: bash
export CC="gcc-8"
export CXX="g++-8"
export CPP="g++-8"
export LD="gcc-8"
export LDFLAGS="-Wl,-rpath,/usr/local/opt/gcc/lib/gcc/8/"
.. note::
Replace the version ("8") in the above lines with the actually installed
gcc version!
Then follow the instructions in :ref:`source_install`.
clang/LLVM
~~~~~~~~~~
.. code-block:: bash
brew update
brew install llvm
export CC='/usr/local/opt/llvm/bin/clang'
export CXX='/usr/local/opt/llvm/bin/clang++'
export CXX11='/usr/local/opt/llvm/bin/clang++'
export LDFLAGS='-L/usr/local/opt/llvm/lib -Wl,-rpath,/usr/local/opt/llvm/lib -lgomp'
export CPPFLAGS='-I/usr/local/opt/llvm/include -stdlib=libc++'
Then follow the instructions in :ref:`source_install`.
.. note::
The MacOS wheel, which we provide on PyPI (for pip installation)
was built using clang/LLVM. So it may happen that you run into binary
incompatibilities if you use a different compiler suite on your computer.
In such cases it may be necessary to build cysgp4 from source using
your own compiler. Sometimes even different compiler versions
(e.g. gcc 6.3 instead of gcc 6.4) can lead to problems.
Please write a ticket, if you run into trouble.
.. note::
Again, if you're on Anaconda, things get (often) much simpler:
.. code-block:: bash
conda install -c conda-forge gcc
This will install the gcc compiler suite into your Anaconda installation
and the instructions in :ref:`source_install` should work out-of-the-box.
If you prefer clang/LLVM, the following should install the necessary
conda packages:
.. code-block:: bash
conda install -c conda-forge clang_osx-64 clangxx_osx-64 llvm-openmp openmp
The `cysgp4` package on `conda-forge `_
was created using the latter approach.
.. _testing_installed_cysgp4:
Testing an installed cysgp4
----------------------------
The easiest way to test if your installed version of cysgp4 is running::
pytest --pyargs cysgp4.tests
.. note::
This way of running the tests may not work if you do it in the
cysgp4 source distribution directory.
It is also possible to use the `~cysgp4.test()` function::
import cysgp4
cysgp4.test()
but currently, this will only work, if the user has `Astropy`_ installed
(this may change soon).
The tests should run and print out any failures, which you could report at
the `cysgp4 issue tracker `_.
If you prefer testing on the command line and want to develop in the source
code, you can also utilize `tox `_ and
run the following in the source directory:
.. code-block:: bash
tox -e test