I have updated the PDE-separation branch again, it is now in
'pde-separate-v2'.
In case you have sympy's sources already checked out:
$ git remote add plaes git://github.com/plaes/sympy.git
$ git checkout -b pde origin/pde-separate-v2
About API:
I have two higher-level functions called: pde_separate_add and
pde_separate_mul. Both functions return list with two separated
expression on success, and None on failure.
_add substitutes F(x, y) = X(x) + Y(y) into equation and _mul case does
F(x, y) = X(x)*Y(y).
The main variable separation algorithm is in the _separate() function.
This algorithm is still WIP (so I added a failing testcase too, feel
free to fix it :) )
Two examples from doctest:
>>> from sympy import *
>>> x, t = symbols('xt')
>>> u, X, T = map(Function, 'uXT')
>>> eq = Eq(Derivative(u(x, t), x), E**(u(x, t))*Derivative(u(x, t), t))
>>> pde_separate_add(eq, u(x, t), [X(x), T(t)])
[D(X(x), x)*exp(-X(x)), D(T(t), t)*exp(T(t))]
>>> from sympy import *
>>> x, y = symbols('xy')
>>> u, X, Y = map(Function, 'uXY')
>>> eq = Eq(Derivative(u(x, y), x, 2), Derivative(u(x, y), y, 2))
>>> pde_separate_mul(eq, u(x, y), [X(x), Y(y)])
[D(X(x), x, x)/X(x), D(Y(y), y, y)/Y(y)]
So, what do you think about API?
Also, because both _add and _mul functions are fairly similar, would it
make sense to add also, pde_separate(strategy='mul | add') ??
Cheers,
Priit :)
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"sympy" group.
To post to this group, send email to sympy@googlegroups.com
To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com
For more options, visit this group at http://groups.google.com/group/sympy?hl=en
-~----------~----~----~----~------~----~------~--~---
