id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
20455 rewrite buggy Expression.coefficients() without Maxima rws "At the moment the `ex1.coefficients(ex2)` method uses pexpect-Maxima to get a coefficient list of a symbolic expression `ex1` when seen as a polynomial in `ex2` but the list is wrong whenever the exponent of `ex2` is nonnumeric:
{{{
sage: var('a, x')
(a, x)
sage: f = a*x - x^x
sage: f.coefficient(x^x)
-1
sage: f.coefficients(x)
[[-x^x, 0], [a, 1]]
}}}
It should not be difficult to rewrite `coefficients` using wildcard power search and the `coefficient` method (which doesn't use Maxima)." defect closed major sage-duplicate/invalid/wontfix symbolics invalid paulmasson N/A