McLaughlin, James on Mon, 08 Dec 2003 11:41:00 +0100

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RE: bnrisprincipal to slow

How does 

 GP/PARI CALCULATOR Version 2.2.6 (development CHANGES-1.756)
                i386 running cygwin (ix86 kernel) 32-bit version
              compiled: May 28 2003, gcc-3.2 20020927 (prerelease)
                (readline v4.3 enabled, extended help available)

compare with version 2.2.7?

I am trying to find a set of fundamental units for the field generated by a degree 37 polynomial

 (discriminant 10^36*37^37) and it has been running for about 8 days now. A similar computation for a polynomial of degree 31 took about a day.  I am wondering if version 2.2.7 would speed things up considerably or perhaps the computations have run into some kind of loop?  My code for this is:

a=(x + 2*I)^n;
b=(x - 2*I)^n;
f=     round ( real(  (a + b)/2 - (a - b)/(4*I)   ))   ;
fus=    bnfinit( f,1).fu    ;

Jimmy Mc Laughlin.


First make absolutely sure you are using the CVS version of PARI [ headers
should read something like

        GP/PARI CALCULATOR Version 2.2.7 (development CHANGES-1.873)

with possibly a slightly lower patchlevel. ]

The development version is orders of magnitude faster than the stable ones
(2.1.*) for algebraic number theory (and a few other things).