Igor Schein on Mon, 21 Oct 2002 11:50:13 -0400


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Re: polredabs(,16) for quadhilbertreal


On Sat, Oct 19, 2002 at 06:42:20PM +0200, Bill Allombert wrote:
> Hello PARI/GP developers,
> 
> quadhilbertreal call polredabs0  via makescind via rnfpolredabs.
> 
> Should it be possible to use polredabs(,16) to avoid hanging on the factorization ?

Based on my experience, as of current implementation, I wouldn't want
to see it as a default, as long as it's not a default for polredabs()
itself.  I've see polynomials where polredabs(,16) is a noop until
you, say, increase primelimit.  So maybe, make lazy factorization a
default for all related functions, but leave an option to do a
complete one with a certain flag.  Or, even make lazy factorization a
global default().  As long as there's consistency, I have no
problem. 

Right now, for example, galoisinit() does lazy factorization by
default.  I don't know if there're exist cases where that failes, or
when the size of automorphisms is unnecessarily large because it just
needed 1 more smallish factor.  Bill surely can clear the fog for me
here.  However, I can speak confidently for polredabs().

Igor