Re: poldisc

[Igor Schein <igor@txc.com>]

On Wed, Jan 20, 1999 at 09:38:11PM -0500, Ilya Zakharevich wrote:
> a) It looks like you cannot advice poldisc() which variable you are interested in.
> 
> b) I tried to do
> 
> p=a*x^3+b*x^2*y+c*x*y^2+d*y^3 + e*x^2+f*x*y+g*y^2 + h*x+i*y + h
> di=poldisc(p)
> 
> and it will not work with 16M stack, and does not finish in half an hour
> anyway.
> 
> Should it be *that* resource-intensive?  I think I may be able to calculate
> given a sheet of paper...
> 
> Ilya

With the latest patch level, I get this:

% gp-sta -q -f
? p=a*x^3+b*x^2*y+c*x*y^2+d*y^3 + e*x^2+f*x*y+g*y^2 + h*x+i*y + h;
? #
   timer = 1 (on)
? poldisc(p,y);
time = 20 ms.
? poldisc(p,x);
  ***   the PARI stack overflows !!!

  ***   Warning: doubling stack size; new stack = 8000000.

However, if I introduce y to PARI before defining p, everything works
fine.  Maybe I missed something in the previous discussion, but from
what I understood I thought one doesn't need to *introduce* variables
any more, now that poldisc() takes 2 arguments.

Thanks

Igor