Re: Bug in Mod (2.0.15)

[Ilya Zakharevich <ilya@math.ohio-state.edu>]

On Fri, May 05, 2000 at 10:39:47AM +0200, Bill Allombert wrote:
> PARI does not handle sparse polynomials, and this is a big limitation,
> even for moderate input. Probably it is better to implement it before
> Groebner basis.

I do not understand this obsession with sparse polynomials.  As far as
I understand, PARI handles sparse polynomials NOW.  If you encode a
monomial with k variables of total degree d, it cannot take more than
d+2k units of storage.  And this is at worst additive for several
monomials in question.

For me, it *is* support for sparse polynomials.  Well, the constant
could be made slightly better, but this might be more-or-less cutting
corners.

I think other issues would be more important than sparser polynomials.
Say, I tried to check the applicability of claims in
http://calfor.lip6.fr/~jcf/benchs/node4.html by asking Macaulay2 to
gen gb E150 (FGb is claimed to do it in 70sec).  It is already 42
hours on Ultra5, and it is still running (without swapping yet, but it
is close: SIZE=99M, RES=78M with 128M ram).

Ilya