On Sun, 20 Nov 2005, Richard Fateman wrote:
> Probably they don't have bugs. I suspect the programs that call them have
> bugs in the way they are set up. If you have exactly rational functions
> of simple variables, I think they all work.
> If there are bugs in such circumstances, I am not aware of them.
> (In particular, such reported bugs usually accuse subres of having
> a bug. Since it is about 15 lines of code, that seems implausible.)
>
> The best gcd algorithm depends on the nature of the input. Dense?
> Many variables? Large GCD or probably GCD=1? Large coefficients?
>
> Two suggestions: EEZGCD if sparse. Perhaps SUBRES, if the GCD is large.
Many thanks for your advice.
In simple cases, polynomials have 1 variable, degree 10 - 20, and are
dense. This cannot be difficult.
In other cases, there are 2 - 3 variables (well, maybe, sometimes, 4), and
polynomials are sparse. Coefficients are moderately large (in most cases a
32-bit integer will suffice; there may be rare exceptions). Nobody can
tell if GCD will be large: in many cases, it will be 1; sometimes, maybe,
large.
So, I'll try eezgcd. Right?
Thanks,
Andrey