derived

[Riccardo Maffei]

Hail to all.
I have a problem that I hope could help me to resolve.
I should write a small program that calculates the derived symbolic of
a given function under form of bootlace.
Where could I find the proper information?
Thank you for the help.
Ric.

 

[Joona I Palaste]

Hail to all.
I have a problem that I hope could help me to resolve.
I should write a small program that calculates the derived symbolic of
a given function under form of bootlace.
Where could I find the proper information?
Thank you for the help.
Ric.

This is quite a non-trivial problem. It doesn't depend so much on C
than on finding a good algorithm to calculate symbolic derivatives in
the first place. Therefore I think you should first ask on
comp.programming or comp.theory to find out an algorithm, and then come
back here to ask questions about how to implement it in C.

--
/-- Joona Palaste ([email protected]) ---------------------------\
| Kingpriest of "The Flying Lemon Tree" G++ FR FW+ M- #108 D+ ADA N+++|
| http://www.helsinki.fi/~palaste W++ B OP+ |
\----------------------------------------- Finland rules! ------------/
"Immanuel Kant but Genghis Khan."
- The Official Graffitist's Handbook

 

[Julian V. Noble]

Hail to all.
I have a problem that I hope could help me to resolve.
I should write a small program that calculates the derived symbolic of
a given function under form of bootlace.
Where could I find the proper information?
Thank you for the help.
Ric.

The programming methods for symbolic manipulation are basically the same
as for writing compilers. Namely you have to recognize a specific kind
of string and perform a specific transformation (or set of transformations)
on it. I touched on this very problem in a recent column, "Recurses!", in
Computing in Science and Engineering (IEEE/AIP).

Probably an expert at YACC could tell you how to do it with that
specialized program.

Further information can be obtained from sci.math.symbolic .

--
Julian V. Noble
Professor Emeritus of Physics
(e-mail address removed)
^^^^^^^^^^^^^^^^^^
http://galileo.phys.virginia.edu/~jvn/

"Science knows only one commandment: contribute to science."
-- Bertolt Brecht, "Galileo".

 

[ipo]

Hail to all.
I have a problem that I hope could help me to resolve.
I should write a small program that calculates the derived symbolic of
a given function under form of bootlace.
Where could I find the proper information?
Thank you for the help.
Ric.

As I was saying in the Italian version of your original posting, I assume
that the program should be able to differentiate only polynomials and not
algebraic or transcendental functions.

If that is the case, the rules of differentiation for constants, sums,
differences, products, quotients, and powers in your textbook pretty much
spell out the algorithm that you're looking for. I haven't done any symbolic
computation in C so the simplest example that I know of is in the book LISP
by Patrick Winston published by Addison-Wesley. That should give you enough
to get you started.

ipo