#12766: Better plotting for elliptic curves
-------------------------------+--------------------------------------------
Reporter: roed | Owner: cremona
Type: enhancement | Status: new
Priority: minor | Milestone: sage-5.0
Component: elliptic curves | Keywords:
Work issues: | Report Upstream: N/A
Reviewers: | Authors:
Merged in: | Dependencies:
Stopgaps: |
-------------------------------+--------------------------------------------
The plot for `EllipticCurve('448c6') looks like a vertical line. The
reason is that `plot` contains
{{{
d = 4*x**3 + (a1**2 + 4*a2)*x**2 + (2*a3*a1 + 4*a4)*x + (a3**2 + 4*a6)
r = d.roots(multiplicities=False)
r.sort()
if xmax is None:
xmax = r[-1] + 2
xmax = max(xmax, r[-1]+2)
if xmin is None:
xmin = r[0] - 2
xmin = min(xmin, r[0]-2)
}}}
When `d` has only one real root, this approach doesn't work that well.
One suggestion would be to also require that the plot contains the flex
points, which can be found from the 3-division polynomial.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/12766>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
