John Cremona on Wed, 15 Feb 2012 20:53:22 +0100

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Re: Elliptic modular functions

I agree with the proposal to have a new prefix, not ell-, to these
functions.  Perhaps mod- would be best.  I always thought the elliptic
curve chapter in the manual was strange having these functions which
neither create nor act on elliptic curves.

If there is a deprecation policy, the old versions of the names should
still be allowed for a while.


On 15 February 2012 18:04, Andreas Enge <> wrote:
> On Wed, Feb 15, 2012 at 06:27:27PM +0100, Karim Belabas wrote:
>> eta(x, 1) ?
>> These are exported as weber(x, 0 / 1 / 2)
> Ah, sorry! I had been looking for them under "ell...", together with ellj and
> ellsigma. (And even got side tracked by elleta, but which is the other one.) Would
> it make sense to rename them with a common prefix such as "mod"? Or add "ell"
> to all of them?
>> > ellgamma2, ellgamma3.
>> I'm not sure what these two denote: maybe elleisnum(E, 2 / 3, 1)  ???
> No, j^1/3 and (j-1728)^1/2, respectively. Both occur as class invariants, and
> the main interest of the former is that j=gamma2^3 is a good computational
> definition of j.
>> So it seems they are all already exported. It would be interesting to
>> test and optimize them, though...
> Okay; but this is even less urgent then, since our students can already
> start using the existing functions. Thanks for the pointers!
> Andreas