Make Sage compatible with PARI stable and PARI master

[jdemeyer]

This makes a few changes to Sage to allow it to be compatible with both PARI stable 2.9.3, as well as PARI git master (see #23544).

With "compatible", I mean that Sage builds and that all doctests are mathematically correct. So, doctests might fail but only because one correct answer is replaced by a different correct answer.

The main change is one call to ellwp(), where the current PARI version returns a value which is a factor 2 too small. Interestingly, Sage compensates for this by using a wrong formula later, to get correct results anyway.

CC: @infinity0 @kiwifb @JohnCremona

Component: packages: standard

Author: Jeroen Demeyer

Branch/Commit: c214994

Reviewer: François Bissey

Issue created by migration from https://trac.sagemath.org/ticket/23796

[jdemeyer]

Branch: u/jdemeyer/ticket/23796

[kiwifb]

Commit: 108ff2e

[kiwifb]

New commits:

a668387	Fix elliptic_exponential()
3d582ec	Don't use undocumented nf[7] in Simon's scripts
108ff2e	Use "abs tol" for clarity

[jdemeyer]

New commits:

a668387	Fix elliptic_exponential()
3d582ec	Don't use undocumented nf[7] in Simon's scripts
108ff2e	Use "abs tol" for clarity

[kiwifb]

comment:6

Looks good to me. Passes basic tests.

[kiwifb]

Reviewer: Francois Bissey

[jdemeyer]

comment:7

Thanks! I hope this helps.

[jdemeyer]

Changed reviewer from Francois Bissey to François Bissey

[vbraun]

comment:8

On 32-bit:

File "src/sage/schemes/elliptic_curves/period_lattice.py", line 136, in sage.schemes.elliptic_curves.period_lattice._ellwp_flag1
Failed example:
    _ellwp_flag1(E, E((0,1)).elliptic_logarithm())
Expected:
    (-7.71860259319095 E-30, 2.00000000000000)
Got:
    (-7.71860260 E-30, 2.00000000000000)

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

d80d583

32-bit doctest fix

[sagetrac-git]

Changed commit from 108ff2e to d80d583

[jdemeyer]

comment:10

Obvious fix.

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1 and set ticket back to needs_review. This was a forced push. New commits:

c214994

32-bit doctest fix

[sagetrac-git]

Changed commit from d80d583 to c214994

[jdemeyer]

comment:14

Pending because of upstream discussion at sagemath/cypari2#38

[jdemeyer]

comment:15

OK, the ellwp() bug is now also fixed upstream in cypari2. The simplest way forward is probably to merge this ticket as-is and then revert the ellwp() fix in Sage when we upgrade cypari2.

[kiwifb]

comment:16

Because you had left the ticket on positive review Volker already included it in his current merge, we can expect it to be closed fixed in his next round of closure - unless some new problem crop up.

[vbraun]

Changed branch from u/jdemeyer/ticket/23796 to c214994