Arcfile: Tools for working with low-level data from GCP

The arcfile package is a library for reading raw data from telescopes
using the Generic Control Program (GCP).  Examples are POLARBEAR,
the BICEP/Keck series of experiments and the South Pole Telescope
(see Story et al., http://arxiv.org/abs/1210.4966).  GCP writes data
in a frame-based file format known as an arc file ("archive file").
The arcfile package contains C code for efficiently reading compressed
or uncompressed arc files; binary executables to export arc file
data to other formats; and interfaces to work with arc file data in
Matlab, Octave, and Python.

This README applies to initial unversioned dump of the arcfile
package into Github.

Arc file support:
---------------------

The arcfile code is known to work with arc files written by the
BICEP series of experiments, BICEP1, BICEP2, the Keck Array, and
BICEP3.  It has not been tested on arc files from other experiments.
It can read gzipped arc files directly.  There is some support for
other compression types, although these are not currently well
integrated into the build system.

Platforms supported:
---------------------

The arcfile package supports Linux and other Unix-like systems such
as Mac OSX.  Building on Windows should be possible with MinGW, but
this has not been attempted.

Command-line utilities:
---------------------

* arc2txt: export to plain text
* arc2dir: export to dirfile (http://getdata.sourceforge.net/dirfile.html)
* dumparc: export to hex-encoded values (historical)
* arcfile: export to multiple formats

Matlab and Octave interfaces:
--------------------

The C library is wrapped with a MEX function, readarc.  Rather than using
this directly, the M-file function load_arc should be used to load arc file
data into Matlab or Octave.

Python interface:
--------------------

The arcfile package provides the Python module arcfile, which can be used
to load arc file data into Python (tested with 2.7) with numpy.

Development:
--------------------
The code is hosted on GitHub at https://github.com/rwogburn/gcp-arcfile.