On Oct 12, 1:25 pm, "Joel B. Mohler" <[EMAIL PROTECTED]> wrote:
[...]
> Suppose I had a poly ring with 19 variables and one of them was named "y".
> How would I get the coefficient for y^0 in your syntax? (That is, the
> constant term in k[y][...].) This is the sticking point in what is currently
> implemented.
No, that would be the constant term in k[...][y]. The syntax would
then be:
poly.coeff({ a for a in poly.parent().generators() if a != y }, 1)
(i.e., all variables except y are allowed)
except that python doesn't like set comprehension (why not? is there
an unordered list type with quick membership test?), so we might want
to make it a list instead:
poly.coeff([ a for a in poly.parent().generators() if a != y ], 1)
If that is the most common usage scenario you have in mind, then this
notation might be a tad wasteful. Would surgery on poly.dict() solve
your problems?
Incidentally, poly.coefficient does have documentation. The behaviour
you describe is a bug relative to that description. The alternative
behaviour that you describe, nor mine, is in line with the definition
given there either.
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