add Weierstrass cubic curve class

[katestange]

Add cubic Weierstrass curve class, which can initialize either an elliptic curve or a singular cubic. Implement basic functionality for singular cubic curves, such as: change of Weierstrass form, addition of points, etc.

CC: @adeines @sagetrac-ekin @katestange @sagetrac-jmypark

Component: elliptic curves

Keywords: singular, weierstrass form

Issue created by migration from https://trac.sagemath.org/ticket/11823

[4dfe6752-6233-4f7f-8e0e-e1363b12c1b7]

Replaces previous

[9030bafb-df88-4adc-89f7-88a82c179223]

comment:3

Attachment: trac_11823_singular_elliptic_curves.patch.gz

[9030bafb-df88-4adc-89f7-88a82c179223]

replaces previous patch

[katestange]

Attachment: trac_11823_singular_elliptic_curves.2.patch.gz

replace previous (now a class, not a flag)

[4dfe6752-6233-4f7f-8e0e-e1363b12c1b7]

Attachment: trac_11823_singular_weierstrass_curves_class.patch.gz

Attachment: trac_11823.patch.gz

Replaces previous patch

[4dfe6752-6233-4f7f-8e0e-e1363b12c1b7]

comment:4

Instead of setting a flag, we have a new class WeierstrassCubic which handles both EllipticCurves and SingularWeierstrassCurves.

[katestange]

Attachment: Trac_11823.patch.gz

replace previous

[katestange]

Description changed:

--- 
+++ 
@@ -1 +1 @@
-Add a flag which allows an elliptic curve to initialize a singular cubic Weierstrass form and implement basic functionality, such as:  change of Weierstrass form, addition of points, etc.
+Add cubic Weierstrass curve class, which can initialize either an elliptic curve or a singular cubic.  Implement basic functionality, such as: change of Weierstrass form, addition of points, etc.

[katestange]

Description changed:

--- 
+++ 
@@ -1 +1 @@
-Add cubic Weierstrass curve class, which can initialize either an elliptic curve or a singular cubic.  Implement basic functionality, such as: change of Weierstrass form, addition of points, etc.
+Add cubic Weierstrass curve class, which can initialize either an elliptic curve or a singular cubic.  Implement basic functionality for singular cubic curves, such as: change of Weierstrass form, addition of points, etc.

[katestange]

Attachment: Trac_11823.2.patch.gz

replaces previous

[katestange]

Attachment: Trac_11823.3.patch.gz

Replaces previous

[vbraun]

comment:7

Do you have any plans for this ticket? Is it finished, needs work, abandoned?

Having a WeierstrassCubic class hierarchy sounds like a good idea but it needs to be integrated.

Also, right now its one huge patch bomb. It would be nice if it could be split into manageable pieces, for example start with WeierstrassCubic_generic only and then build on top of that.

[JohnCremona]

comment:8

Replying to @vbraun:

Do you have any plans for this ticket? Is it finished, needs work, abandoned?

Who is "you"?

Having a WeierstrassCubic class hierarchy sounds like a good idea but it needs to be integrated.

That's a necessary condition, certainly.

Also, right now its one huge patch bomb. It would be nice if it could be split into manageable pieces, for example start with WeierstrassCubic_generic only and then build on top of that.

I myself don't need this. I'm also worried that since elliptic curves would be a special case, this would add a new layer of code for all elliptic curves, slowing them down, which would be a Bad Thing.

Anyway, it's up to the people who worked on this in the frst place to make their case!