Status: Accepted
Owner: ----
Labels: Type-Defect Priority-Medium
New issue 3122 by [email protected]: coeff wish list
http://code.google.com/p/sympy/issues/detail?id=3122
Should coeff() try to extract terms without doing an actual expansion? e.g
Aaron cites from Maple:
```
A more difficult example: the polynomial does not need to
be expanded for coeff(p, x^n) to work.
> q:=3*a*(x + 1)^2 + sin(a)*x^2*y - y^2*x + x - a;
q:=3*a*(x + 1)^2 + sin(a)*x^2*y - y^2*x + x - a
> coeff(q, x);
6*x - y^2 + 1
```
[and Aaron continues to say]
In theory, it should be possible to compute this without expanding the
entire expression, by simply computing the multinomial coefficient that we
want for each term.
Another thing that it could do is pick up terms that appear in the same
proportion as an Add pattern, e.g.
(2 + 2*x + y*(x + 1)).coeff(x + 1) --> 2 + y
--
You received this message because you are subscribed to the Google Groups
"sympy-issues" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sympy-issues?hl=en.
