Karim BELABAS on Mon, 1 Feb 1999 18:30:39 +0100 (MET)

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Re: Primelimit

> > I don't understand what you want to achieve by artificially lowering the
> > number of primes available to some functions. Could you give more details ?
> If I understand Gerhard correct, some functions take primelimit not as
> an advice about the number of available primes, but as a directive to
> loop over these primes.
> Suppose I want to have a table of primes up to 1e9 (very easy with the
> current PARI), say, to use forprime() with big primes.  This may
> significantly slow down the functions which loop over *all* existing
> primes.

I don't think there's any function like that. I'll check that. 
The only exception I can think of is factor(x, 0), and you can use
factor(x, bound) to achieve exactly what you want [the default factor will
only trial divides by the first 1000 primes or so before trying more
elaborate stuff].

Karim Belabas                    email: Karim.Belabas@math.u-psud.fr
Dep. de Mathematiques, Bat. 425
Universite Paris-Sud             Tel: (00 33) 1 69 15 57 48
F-91405 Orsay (France)           Fax: (00 33) 1 69 15 60 19
PARI/GP Home Page: http://hasse.mathematik.tu-muenchen.de/ntsw/pari/