I have seen some web pages defining that current sinking and current sourcing are same. But the truth is that they are different. This is a tutorial about current sinking and current sourcing in Integrated Circuits(IC).
Current Sinking & Current Sourcing Tutorials
More example programs for Octave has been posted in my wiki page. Please vist
If you don’t know about Octave, I have been maintaining a wiki page for Octave. See the link below
http://jeffrey.co.in/wiki/doku.php/experiments_using_octave_for_b-tech_course