id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
8997 riemann_roch_basis is implemented incorrectly in sage was AlexGhitza "See the file schemes/plane_curves/projective_curve.py, where it says
{{{
The following example illustrates that the Riemann-Roch space
function in Singular doesn't *not* work correctly.
::
sage: R. = GF(5)[]
sage: f = x^7 + y^7 + z^7
sage: C = Curve(f); pts = C.rational_points()
sage: D = C.divisor([ (3, pts[0]), (-1,pts[1]), (10, pts[5]) ])
sage: C.riemann_roch_basis(D) # output is random (!!!!)
[x/(y + x), (z + y)/(y + x)]
The answer has dimension 2 (confirmed via Magma). But it varies
between 1 and quite large with Singular.
}}}
The problem can be solved by learning how the relevant code in Singular works then correctly wrapping it.
'''Apply''': [attachment:trac_8997_fix_rr_basis_and_doc.patch]" defect closed major sage-4.6.2 algebraic geometry fixed rkirov minz OleksandrMotsak sage-4.6.2.alpha1 Moritz Minzlaff David Joyner, Oleksandr Motsak N/A