Re: polcyclo: overflow in precp().

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

On Fri, Oct 14, 2022 at 10:33:51AM -0400, Max Alekseyev wrote:
> Hello,
> 
> Can anything be done about this error?
> 
> ===
> ? allocatemem(2^31)
>   ***   Warning: new stack size = 2147483648 (2048.000 Mbytes).
> ? polcyclo(524308,10+O(2^2))
>   ***   at top-level: polcyclo(524308,10+O(2^2))
>   ***                 ^--------------------------
>   *** polcyclo: overflow in precp().
>   ***   Break loop: type 'break' to go back to GP prompt
> break>
> ===

You can try

mypolcyclo(n,a,p,e)=
{
  my(P=1,v=valuation(a,p));
  if(v==0
    ,polcyclo(n,a+O(p^e))
    ,fordiv(n,d,P*=(if(d*v<e,a^d,0)-1)^moebius(n/d));
    P+O(p^e))
}

? mypolcyclo(524308,10,2,100)
%31 = 1+2^2+2^3+2^5+2^6+2^8+2^12+2^13+2^15+2^17+2^20+2^21+2^26+2^27+2^28+2^29+2^30+2^32+2^33+2^37+2^41+2^43+2^46+2^48+2^51+2^52+2^53+2^54+2^55+2^56+2^59+2^63+2^65+2^70+2^74+2^75+2^78+2^84+2^85+2^89+2^90+2^92+2^93+2^94+2^96+2^97+2^98+O(2^100)

Cheers,
Bill.