[Maxima] sdiff, differentiating expressions
fateman at cs.berkeley.edu
Thu May 14 17:28:12 CDT 2009
the program sdiff, in the source file comm.lisp
has gotten corroded over the last few years by patches put in (probably)
the wrong places.
I rewrote it in the file
http://www.cs.berkeley.edu/~fateman/lisp/new-sdiff.lisp and moved the
patches off to property lists.
If you have modified sdiff, please check it out.
well, the program sdiff goes through a sequential list of things that
it knows how to differentiate, like
plus, times, "rational functions", some other things, and then a big
multi-way branch to do sin,cos,exp,...
Now over the years people have put into "some other things" all kinds of
rare and unusually occurring things.
Like hypergeometric functions, laplace transforms, etc etc.
These patches should come AFTER sin/cos/exp, or at the same time as
sin/cos/exp , or if for some reason
they must have some special checks because of peculiar arguments, they
can be done by a multi-way branch.
See the file for how it can be done.
what do you think?
I have not tried timing tests.
More information about the Maxima