The pyradi toolkit is a Python toolkit to perform optical and infrared radiometry (flux flow) calculations.
The toolkit is available at
http://code.google.com/p/pyradi
See docs at
http://pyradi.googlecode.com/svn//trunk/doc/_build/html/index.html
Visit the google group at http://groups.google.com/group/pyradi-dev
IPython notebooks demonstrating the use of pyradi is available at
https://github.com/NelisW/ComputationalRadiometry#computational-optical-radiometry-with-pyradi
The respective python files all have examples of use and simple test code at the end of each of the files. Execute these python files as scripts to execute the example code, and observe the results.