This is the source code repository for ERFA (Essential Routines for Fundamental Astronomy). ERFA is a C library containing key algorithms for astronomy, and is based on the SOFA library published by the International Astronomical Union (IAU).
ERFA is intended to replicate the functionality of SOFA (aside from possible
bugfixes in ERFA that have not yet been included in SOFA), but is licensed
under a three-clause BSD license to enable its compatibility with a wide
range of open source licenses. Permission for this release has been
obtained from the SOFA board, and is avilable in the LICENSE file included
in this source distribution.
This version of ERFA (v0.0.1) is based on SOFA version "20120301_a", with the differences outlined below.
All references to "SOFA" in the source code have been changed to ERFA, and
functions have the prefix era instead of iau.
To build and install a released version of ERFA in your OS's standard location, simply do:
./configure make make install
If you want to run the tests to make sure ERFA built correctly, before installing do:
make check
If you are using a developer version from github, you will need to first do
./bootstrap.sh before the above commands. This requires autoconf and
libtool.
If you wish to build against the ERFA static library without installing, you
will find it in $ERFAROOT/src/.libs/liberfa.a after running make.
Alternatively, if you wish to bundle the ERFA source code with a separate
package, you can use the source_flattener.py script from the
erfa-fetch repository to combine
the ERFA source code into a single erfa.c source file, and an
erfa.h include file. If possible, however, it is recommended that you
provide an option to use a installed ERFA library, if it is present.
