Description

Healpy provides a python package to manipulate healpix maps. It is based on the standard numeric and visualisation tools for Python, Numpy and matplotlib.

To find find more information about Healpix, please visit its home page at http://healpix.jpl.nasa.gov/.

Characteristics

• pixellisation manipulation (ang2pix, pix2ang, ...)
• spherical harmonic transforms (map2alm, alm2map, synfast, anafast, ... both for temperature and polarisation)
• plotting capabilities (mollweide and gnomonic projection)
• reading and writing of healpix fits maps and alm

Requirements

• Python (tested with 2.4 and 2.5, however see bug for python 2.4 )
• Numpy (tested with version >=1.0.1)
• matplotlib (tested with version >= 0.91.2 up to 0.98.4, Please use latest version
• Note: matplotlib 0.98.3 has a bug preventing mollview to work (infinite recursion in cbook.flatten). Either correct the bug as indicated there or update to more recent version (>= 0.98.4)
• PyFITS
• Note: For healpix map Nside=8192, there is a bug in Numpy preventing pyfits to work. You should upgrade to latest pyfits version (>= 2.1) which provide a workaround.

Healpix C++ library (from HEALPix 2.11) is included in the healpy package, so you don't need to get it separately

Download

The latest (and recommanded version) is healpy 0.9.6.3.

Installation

Download the last version from download tab, for example healpy-0.9.4.tar.gz Then:

tar zxf healpy-0.9.4.tar.gz
cd healpy-0.9.4
python setup.py install

Use the setuptools install option to install healpy in non-standard place, for example:

python setup.py install --install-lib=~/Softs/Python

will install it in ~/Softs/Python

Test the installation with:

import healpy
healpy.mollview(arange(12))

Documentation

• Use the online documentation, accessible with help() (or using the '?' in ipython).

Acknowledgements

Note that, as stated here, publications based on work using the HEALPix software package should include both of the following:

1. an acknowledgment statement - "Some of the results in this paper have been derived using the HEALPix (Górski et al., 2005) package"

The complete reference is:

Górski, K.M., E. Hivon, A.J. Banday, B.D. Wandelt, F.K. Hansen, M. Reinecke, and M. Bartelmann, HEALPix: A Framework for High-resolution Discretization and Fast Analysis of Data Distributed on the Sphere, Ap.J., 622, 759-771, 2005.

2. at the first use of the HEALPix acronym, a footnote placed in the main body of the paper referring to the HEALPix web site - currently http://healpix.jpl.nasa.gov

As healpy is based on HEALPix Software (the C++ library), the same condition applies to it.