riemann roch basis

asked 2012-06-12 16:41:22 -0500

gato.lif gravatar image

updated 2015-01-31 13:11:05 -0500

FrédéricC gravatar image

i have a question with this code (i speak little english)

F.<w>=GF(4,'w')
R.<X,Y,Z> = ProjectiveSpace(F,2)
C = Curve(X^2*Y + w*Y^2*Z+ w^2*Z^2*X)
print C.genus()
pts = C.rational_points()
print pts[4]
print pts[5]
D = C.divisor([ (2, pts[4]),(1, pts[5]) ])
print D
print C.riemann_roch_basis(D)

result:

(1 : w : 1)
(w : 1 : 1)
2*(X + Z, Y + (w)*Z) + (X + (w)*Z, Y + Z)
Traceback (most recent call last):    print pts[5]
  File "", line 1, in <module>

  File "/tmp/tmpvyK2s4/___code___.py", line 12, in <module>
    exec compile(u'print C.riemann_roch_basis(D)
  File "", line 1, in <module>

  File "parent.pyx", line 871, in sage.structure.parent.Parent.__getattr__ (sage/structure/parent.c:6648)
AttributeError: 'ProjectiveCurve_finite_field' object has no attribute 'riemann_roch_basis'

why?

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Comments

The [docs](http://www.sagemath.org/doc/constructions/algebraic_geometry.html#riemann-roch-spaces-using-singular) make it seem like it's only wrapped when F is prime.

DSM gravatar imageDSM ( 2012-06-12 16:52:40 -0500 )edit