#7116: Potential bug in elliptic curve pairing code.
-----------------------------+----------------------------------------------
Reporter: was | Owner: davidloeffler
Type: defect | Status: new
Priority: major | Milestone: sage-4.1.3
Component: elliptic curves | Keywords:
Reviewer: | Author:
Merged: |
-----------------------------+----------------------------------------------
Comment(by cremona):
The function P._line(R,Q), as documented, returns the value at Q of a
suitably normalized function on the curve representing the straight line
through P and R, where P and/or R are allowed to be the point O at
infinity but Q is not.
The code as written does not work when Q=O, but this is not documented. I
suggest a fix whereby if Q==O then a ValueError is raised -- this is
stricter than the remedy suggested, but I think more consistent since in
this and similar cases the functions which are being evaluated are all in
the polynomial ring k(x,y) of the curve and so should not be evaluated at
O where they have poles.
I'm also sure that in the places where this function is used, the
condition Q==O does not arise.
I'll make a patch,
John
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/7116#comment:1>
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
-~----------~----~----~----~------~----~------~--~---
