polynomial partial fractions

[Kevin Ryde <user42_kevin@yahoo.com.au>]

I had the urge to break some polynomial ratios into partial fractions.
I thought maybe a vector result of terms which sum to the original.

    p = x^4 / ((1-x)*(1-2*x)*(1 - x - 2*x^3))
    v = polynomial_crack_into_partial_fractions(p)
    v == [ (1/2) / (1-x),
           (1/2) / (1-2*x),
           - (1 + (1/2)*x + x^2) / (1-x-2*x^3) ]
    vecsum(v) == p

What would I look at for such a thing?  I know how to build a matrix for
matsolve() to give the numerators, but perhaps this exists already.
I saw Henri Cohen's cohen.gp ratdec() but it seems to go polroots()
where I had in mind only going as far as can be factorized exactly over
complex or quadratics (so leave the cubic above unchanged).  Could
supply the desired denominators if necessary.



-- 
No, eees hamster.