Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Some documentation clean-up #39043

Merged
merged 2 commits into from
Dec 8, 2024
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
37 changes: 22 additions & 15 deletions src/sage/libs/eclib/interface.py
Original file line number Diff line number Diff line change
Expand Up @@ -267,21 +267,28 @@ def two_descent(self, verbose=True, selmer_only=False, first_limit=20,

- ``selmer_only`` -- boolean (default: ``False``); ``selmer_only`` switch

- ``first_limit`` -- integer (default: 20); bound on `|x|+|z|` in
quartic point search

- ``second_limit`` -- integer (default: 8); bound on
`\log \max(|x|,|z|)`, i.e. logarithmic

- ``n_aux`` -- integer (default: -1); (only relevant for general
2-descent when 2-torsion trivial) number of primes used for
quartic search. ``n_aux=-1`` causes default (8) to be used.
Increase for curves of higher rank.

- ``second_descent`` -- boolean (default: ``True``); (only relevant
for curves with 2-torsion, where mwrank uses descent via
2-isogeny) flag determining whether or not to do second
descent. *Default strongly recommended.*
- ``first_limit`` -- integer (default: 20); naive height bound on
first point search on quartic homogeneous spaces (before
testing local solubility; very simple search with no
overheads).

- ``second_limit`` -- integer (default: 8); logarithmic height bound on
second point search on quartic homogeneous spaces (after
testing local solubility; sieve-assisted search)

- ``n_aux`` -- integer (default: -1); if positive, the number of
auxiliary primes used in sieve-assisted search for quartics.
If -1 (the default) use a default value (set in the eclib
code in ``src/qrank/mrank1.cc`` in DEFAULT_NAUX: currently 8).
Only relevant for curves with no 2-torsion, where full
2-descent is carried out. Worth increasing for curves
expected to be of rank > 6 to one or two more than the
expected rank.

- ``second_descent`` -- boolean (default: ``True``); flag specifying
whether or not a second descent will be carried out. Only relevant
for curves with 2-torsion. Recommended left as the default except for
experts interested in details of Selmer groups.

OUTPUT: nothing

Expand Down
28 changes: 5 additions & 23 deletions src/sage/libs/eclib/mwrank.pyx
Original file line number Diff line number Diff line change
Expand Up @@ -992,29 +992,11 @@ cdef class _two_descent:
points. Useful as a faster way of getting an upper bound on
the rank.

- ``firstlim`` -- integer (default: 20); naive height bound on
first point search on quartic homogeneous spaces (before
testing local solubility; very simple search with no
overheads).

- ``secondlim`` -- integer (default: 8); naive height bound on
second point search on quartic homogeneous spaces (after
testing local solubility; sieve-assisted search)

- ``n_aux`` -- integer (default: -1); if positive, the number of
auxiliary primes used in sieve-assisted search for quartics.
If -1 (the default) use a default value (set in the eclib
code in ``src/qrank/mrank1.cc`` in DEFAULT_NAUX: currently 8).
Only relevant for curves with no 2-torsion, where full
2-descent is carried out. Worth increasing for curves
expected to be of rank > 6 to one or two more than the
expected rank.

- ``second_descent`` -- integer (default: 1); flag specifying
whether or not a second descent will be carried out (yes if
1, the default; no if 0). Only relevant for curves with
2-torsion. Recommended left as the default except for
experts interested in details of Selmer groups.
- ``firstlim``, ``secondlim``, ``n_aux``, ``second_descent`` --
see ``first_limit``, ``second_limit``, ``n_aux``, ``second_descent``
respectively in :meth:`~sage.libs.eclib.interface.mwrank_EllipticCurve.two_descent`
(although ``second_descent`` here is ``1`` or ``0`` instead of ``True`` or ``False``
respectively)

OUTPUT: none

Expand Down
2 changes: 1 addition & 1 deletion src/sage/modules/free_module_element.pyx
Original file line number Diff line number Diff line change
Expand Up @@ -4047,7 +4047,7 @@ cdef class FreeModuleElement(Vector): # abstract base class
Differentiate with respect to var by differentiating each element
with respect to var.

.. seealso:
.. SEEALSO::
tscrim marked this conversation as resolved.
Show resolved Hide resolved

:meth:`derivative`

Expand Down
42 changes: 29 additions & 13 deletions src/sage/schemes/elliptic_curves/ell_rational_field.py
Original file line number Diff line number Diff line change
Expand Up @@ -808,16 +808,28 @@ def two_descent(self, verbose=True,

- ``selmer_only`` -- boolean (default: ``False``); selmer_only switch

- ``first_limit`` -- (default: 20) firstlim is bound
on x+z second_limit- (default: 8) secondlim is bound on log max
x,z , i.e. logarithmic

- ``n_aux`` -- (default: -1) n_aux only relevant for
general 2-descent when 2-torsion trivial; n_aux=-1 causes default
to be used (depends on method)

- ``second_descent`` -- (default: ``True``)
second_descent only relevant for descent via 2-isogeny
- ``first_limit`` -- integer (default: 20); naive height bound on
first point search on quartic homogeneous spaces (before
testing local solubility; very simple search with no
overheads).

- ``second_limit`` -- integer (default: 8); logarithmic height bound on
second point search on quartic homogeneous spaces (after
testing local solubility; sieve-assisted search)

- ``n_aux`` -- integer (default: -1); if positive, the number of
auxiliary primes used in sieve-assisted search for quartics.
If -1 (the default) use a default value (set in the eclib
code in ``src/qrank/mrank1.cc`` in DEFAULT_NAUX: currently 8).
Only relevant for curves with no 2-torsion, where full
2-descent is carried out. Worth increasing for curves
expected to be of rank > 6 to one or two more than the
expected rank.

- ``second_descent`` -- boolean (default: ``True``); flag specifying
whether or not a second descent will be carried out. Only relevant
for curves with 2-torsion. Recommended left as the default except for
experts interested in details of Selmer groups.

OUTPUT:

Expand Down Expand Up @@ -2256,9 +2268,9 @@ def gens(self, proof=None, **kwds):

- ``algorithm`` -- one of the following:

- ``'mwrank_shell'`` -- default; call mwrank shell command
- ``'mwrank_lib'`` -- default; call mwrank C library

- ``'mwrank_lib'`` -- call mwrank C library
- ``'mwrank_shell'`` -- call mwrank shell command

- ``'pari'`` -- use ellrank in pari

Expand All @@ -2268,7 +2280,11 @@ def gens(self, proof=None, **kwds):
- ``use_database`` -- boolean (default: ``True``); if ``True``, attempts to
find curve and gens in the (optional) database

- ``descent_second_limit`` -- (default: 12) used in 2-descent
- ``descent_second_limit`` -- (default: 12); logarithmic height bound on
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Also I notice the default here is 12 instead of 8… changing it would be a functional change though.

Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I would leave it. I don't feel comfortable reviewing such a change.

second point search on quartic homogeneous spaces (after
testing local solubility; sieve-assisted search). Used in 2-descent.
See also ``second_limit``
in :meth:`~sage.libs.eclib.interface.mwrank_EllipticCurve.two_descent`

- ``sat_bound`` -- (default: 1000) bound on primes used in
saturation. If the computed bound on the index of the
Expand Down
Loading