Re: Specialize bivariate FpXY (C library)

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

On Tue, Sep 09, 2014 at 09:28:46PM +0200, Bill Allombert wrote:
> On Tue, Sep 09, 2014 at 01:43:39PM -0400, Dan Nichols wrote:
> > Hello PARI users,
> > 
> > Given an FpXY f(x,y) with main variable x and secondary variable y,
> > I want to get the specialization f(r,y) for some r in Fp. It seems
> > like the function I should use is:
> > 
> >    GEN FpXY_evaly(GEN Q, GEN y, GEN p, long vy) Q an FpXY, returns the
> >    FpX Q(X, y), where
> >    X is the second variable of Q.
> > 
> > I assume vy is supposed to the the variable number for the secondary
> > variable.
> 
> Indeed, this is a bug, the parameter should be called vx.]
> I fixed it in master.
> 
> > When I try to call this function, the return value is
> > always 1.
> 
> Indeed, FpXY_evaly does work when y is 0, however the function works correctly
> in the other case. This is due a bug in the code (we return the leading coef instead
> of the constant coef by mistake).
> 
> Thanks for reporting this issue,

If you did not notice yet, we just released PARI 2.7.2 which fix this issue.

Cheers,
Bill.