The S-Lang Histogram Module Page
Version 0.3.2 released. The main difference between this version and the last is cygwin support.
The histogram module makes several functions available to the S-Lang interpreter for the creation and manipulation of one and two dimensional histograms. Since histograms are essential to the analysis of experimental data, this module should prove useful to anyone analyzing data.
As a simple, but powerful (and useful!) example of the histogram and SLgtk modules, a script (evt2img) was created that reads in a Chandra X-ray Observatory event file and produces a so-called "true-color image" for selected energy bands. The resulting image may be saved in the form of a PNG or JPEG file. For example, evt2img was used to create the following image of the supernova remnant E0102. The image is a bit grainy because of the relatively short exposure of the object.
In contrast, here is an image of the megasecond Chandra observation of the famous supernova remnant Cas A that was published in Nature. It was created using the histogram and png modules. Note that the compact object (probably a neutron star) stands out clearly at the center of this image. You can also see the ``jet-like'' ejecta from the explosion at the lower-right side of the image. For more information about our analysis of this remnant, see either the Nature paper, or the preprint http://arxiv.org/pdf/astro-ph/0608401.pdf.
This page was last updated Dec 2, 2007 by John E. Davis. To comment on it or the material presented here, send email to davis at space mit edu.