WMAP IDL Data Analysis Software V3.1 The WMAP IDL Data Analysis Software is distributed as a gzipped tar file wmap_IDL_v31.tar.gz or as a ZIP file wmap_IDL_v31.zip. Once expanded, the contents will occupy approximately 340 MB. The size of the actual code is small; most of this size is due to a number of reference data files used by the code for reprojection functions. Users who already have a previos version of the distribution can download the much smaller file wmap_IDLpro_v31.tar which contains only the IDL procedures plus any updated reference files. The file news.txt gives a list of changes since the original V1.0 release. This package of IDL routines provides some limited manipulation of the MAP time-ordered data and HEALPix maps. See the list_of_routines file in this directory for some capabilities of the package. Use of the WMAP software, especially for the time-ordered data, requires familiarity with material in the WMAP explanatory supplement at http://lambda.gsfc.nasa.gov/product/map/m_docs.html The following steps are needed to install the WMAP IDL package: 1. You must have purchased an IDL license ( http://www.rsinc.com/ ). If you do not have an IDL license, then you may use the procedures as metacode and convert them to your favorite language. (The MAPVIEW image display widget is available to users without an IDL license using the IDL virtual machine.) The programs should run on IDL V5.3 or later, and have been tested on V5.6 - V6.0(linux) and V5.5 (Solaris and Windows). 2. You must have the following two IDL software packages installed: (1) The IDL Astronomy Library (http://idlastro.gsfc.nasa.gov/homepage.html) using a version later than June 2003. (2) The HEALPix Library (http://www.eso.org/science/healpix/) using version 1.1 or later. 3. You must add the procedures in the /pro subdirectory to your !PATH. For example, if the current (Unix) directory is /home/user/wmap then the following can be placed in your IDL startup file. !PATH = '/home/user/wmap/pro:' + !PATH Alternatively, the IDL_PATH environment variable can be set prior to entering IDL, e.g., setenv IDL_PATH "/home/user/wmap/pro:${IDL_PATH}" 4. The /ref subdirectory must be defined as MAP_REF. For example, if the current directory is /home/user/wmap , then MAP_REF can be defined as follows: setenv MAP_REF /home/user/wmap/ref Users on WINDOWS machines should set this environment variable by going to the Control Panel --> System Properties -- Advanced. For installation problems please contact the LAMBDA suggestion page http://lambda.gsfc.nasa.gov/contact/contact.cfm