# Installation from source code¶

Compiling GammaLib from source is the recommended method to install the package in case that you do not use Anaconda (if you use Anaconda, please follow the instructions at Installing via Anaconda, and better do not try to compile the source code against your Anaconda Python installation). You also need to compile from source if you want to use the development version of GammaLib.

Note

These installation instructions apply to gammalib-1.1.0 and later. gammalib-1.1.0 was built, installed and tested successfully on Debian, Ubuntu, Mandriva, OpenSUSE, Scientific Linux, CentOS, Mac OS X, FreeBSD, and OpenSolaris (using gcc), so hopefully it also installs on your distribution. Windows is not supported. In case you encounter problems, please post a report on the bug tracker or send an e-mail to the mailing list.

## Prerequisites¶

GammaLib should compile on every modern Unix system and on Mac OS X, Windows is not supported. To enable support for FITS file handling the cfitsio library from HEASARC needs to be installed. cfitsio exists on many Linux distributions as a prebuilt library, so in general you can directly install it using your package manager. Make sure that you install the library and the development package, as the cfitsio header file (which usually comes only in the development package) is needed to compiling GammaLib.

If cfitsio is not available as a prebuilt package, or if you encounter some problems with the prebuilt package, cfitsio can be downloaded from http://heasarc.gsfc.nasa.gov/fitsio and installed from the source files (for details, please refer to the installation instructions on the HEASARC site). We recommend installation of cfitsio in the default GammaLib install directory as a shared library by typing

$./configure --prefix=/usr/local/gamma$ make shared
$make install  GammaLib can also benefit from the presence of the readline library that provides line-editing and history capabilities for text input (GammaLib offers however full functionality without having readline installed). readline (which depends on ncurses) is available on most system as a prebuilt library, so also here we recommend to use your package manager to install the libraries if they are not already there. Also here, the readline (and ncurses) development packages are required, so that the header files become available. If readline and ncurses are not available as a prebuilt package, or if you encounter some problems with the prebuilt packages, both libraries can be downloaded from http://ftp.gnu.org/gnu/ and installed from the source files. We recommend to put also those in the default GammaLib install directory /usr/local/gamma. GammaLib includes a Python module that is compatible with Python 2 (version 2.3 or higher) and Python 3 (all versions). To generate the Python module, the Python development package including the Python.h header file needs to be installed on your system. ## Building GammaLib¶ To build GammaLib from the source files, download the latest release tarball, save it in an appropriate location, and type $ tar xvfz gammalib-x.y.z.tar.gz


where x.y.z is the version number of the library. Step in the created directory using

$cd gammalib-x.y.z  and build GammaLib by typing $ ./configure
$make  at the operating system prompt. The configuration command customizes the Makefiles for your particular system, the make command compiles the source files and builds the C++ library and Python module. Type ./configure and not simply configure to ensure that the configuration script in the current directory is used and not some other system-wide configuration script. Note To accelerate compilation you may type $ make -j8


which will instruct the automake system to perform a parallelized compilation, where 8 specifies the maximum number of parallel threads (set this number to about twice the number of cores you have available).

By default, the install directory is set to /usr/local/gamma. To change the install directory, provide an optional --prefix argument, for example

$./configure --prefix=/usr/local  If cfitsio and/or readline is not installed in a standard location for libraries (such as /usr/lib or /usr/local/lib), you can specify the appropriate location(s) using the LDFLAGS (for the library directory) and CPPFLAGS (for the include directory) options $ ./configure LDFLAGS='-L/opt/local/lib' CPPFLAGS='-I/opt/local/include'


You can find a full list of configuration options using

$./configure --help  ## Testing GammaLib¶ Before you install GammaLib you should test the C++ library and Python module by typing $ make check


This will execute an extensive testing suite that should terminate with

===================
All 21 tests passed
===================


or

============================================================================
Testsuite summary for gammalib 1.1.0
============================================================================
# TOTAL: 21
# PASS:  21


Eventually, loading the shared cfitsio and/or readline libraries may fail during the test if the libraries are not located in standard locations. In this case, add the library directories to the LD_LIBRARY_PATH environment variables (DYLD_LIBRARY_PATH on Mac OS X), e.g.

$export LD_LIBRARY_PATH=/opt/local/lib:$LD_LIBRARY_PATH


## Installing GammaLib¶

Now you are ready to install GammaLib by typing

$make install  at the operating system prompt. You may need to prepend a sudo in case that you need administrator privileges to access the install directory. If you do not have such privileges, chose an install directory that you can access using the --prefix option. ## Setting up your environment¶ Before using GammaLib you have to setup some environment variables. This will be done automatically by an initialisation script that will be installed in the bin directory. Assuming that you have installed GammaLib in the default directory /usr/local/gamma you need to add the following to your $HOME/.bashrc or $HOME/.profile script on a Linux machine: export GAMMALIB=/usr/local/gamma source$GAMMALIB/bin/gammalib-init.sh


If you use C shell or a variant then add the following to your $HOME/.cshrc or $HOME/.tcshrc script:

setenv GAMMALIB /usr/local/gamma
source $GAMMALIB/bin/gammalib-init.csh  ## Installing documentation¶ Note The documentation of the latest GammaLib release can be found at http://cta.irap.omp.eu/gammalib/. The documentation corresponding to the git development branch can be found at http://cta.irap.omp.eu/gammalib-devel/. You can however also install the GammaLib documentation locally on your machine, and this section describes how to do that. The GammaLib documentation is shipped together with the source code and will be installed in the directory $(prefix)/share/doc/gammalib/html, where $(prefix) is the installation base path, by default /usr/local/gamma. This comprises user documentation and code documentation. To build the user documentation you need the Sphinx reStructuredText documentation generator installed (see http://sphinx-doc.org/rest.html for more information). Code documentation is based on Doxygen, which also needs to be installed on your system (see http://dogygen.org to download and install the Doxygen package). Doxygen will scan the source files for code annotations, and compiles a complete documentation of the implemented C++ classes in a set of html pages. In addition, it will create a set of man files that can be accessed using the man command. To build and install all documentation, type the following $ ./configure
$make doc$ make install


To build only user documentation, type

$./configure$ make sphinx
$make install  and to build only Doxygen documentation, type $ ./configure
$make doxygen$ make install


The Doxygen documentation will be installed into $(prefix)/share/doc/gammalib/html/doxygen and can be browsed using a regular web browser. To check man support, type for example $ man GObservations


and you should see the documentation for the GObservations C++ class.