Hi,

I have been writing some code that can differentiate expressions.
for instance:  x^3 ->  3*x^2.


Here is the code:
http://rubyforge.org/cgi-bin/viewcvs.cgi/projects/symbol_solver/test_nodes.rb?rev=1.22&cvsroot=prime&content-type=text/vnd.viewcvs-markup


Still some unsolved issues:
1. reduce  2x+2x  into 4x..  is not implemented.
2. sin/cos/tan  is not implemented.
3. complex numbers is not used in this implementation.


However code is simple.. and somebody may find usage of it.
Im open for suggestions. Patches are welcome.

Open Questions:
1. What direction should this evolve?
2. Any ideas how to reduce 2x + 2x into 4x ?
3. Is this correct math?

--
Simon Strandgaard