Introducing Cmap Version 1.2

Click here to download cmap.f.

What it does

Cmap is a is a code that generates maps of the microwave background, given a set of Cl's such as those generated by the CMBFAST code. It is an implementation of the algorithm developed by Muciaccia, Natoli, and Vittorio in astro-ph/9703084 , which employs a fast Fourier transform routine and operates in l^3 time. This allows for the generation of a maps of resolution l = 1024 on a time scale on the order of half an hour. Eventually we hope to replace this version with a program that operates in (l log l)^2 time. So it pays to keep an eye out for updates.

How to use it

Cmap can be downloaded from this cite. It is provided as a compressed file which can be unziped into a single fortran file and then compiled using fortran 77. That is type:

gunzip cmap.for.z
f77 -o cmap cmap.for

and you'll have a fully functional version of Cmap. All routines used by cmap are contained within this file.

How to run it

To run Cmap simply type cmap and answer the questions as you are prompted. If Cl's are read in from a file the file must be in the CMBFAST format, that is an ASCII file in which the first column contains the l value and the second Cl*l(l+1)/(4 pi), with l beginning at 2.

What output is available

The output from cmap can be in one of three forms: an ASCII file which contains pixels indexed by theta-phi coordinates, an ASCII file that uses the COBE pixel format, and an a binary file that uses COBE pixels and can be interfaced with the idl routine developed for displaying output from Cmap.

COBE resolution level is defined st the number of pixels about the circumference of the map is 4*(2^(resolution-1)) for l = 1048 = 2^10 then, the most appropriate value would be resolution = 9.

Cmap Technical Information

Is available by clicking here.

Something I need to do

Is thank the NSF for funding me with a graduate fellowship while I was working on this project.

Back to the CfPA Home Page
Please address all Cmap questions to
Last Updated: Nov 23 1997