Bill Allombert on Tue, 09 Sep 2014 21:28:48 +0200

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Re: Specialize bivariate FpXY (C library)

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,