That's actually trivially simple: if [f1,f2,f3] is the basis of your Riemann-Roch space, you just consider the map defined by [f1:f2:f3]. So you lift f1,f2,f3 to rational functions on the affine space that contains your curve: you just take the rational function representation and forget the algebraic relations between the variables.
f1, f2, f3 are univariate polynomials (say in y) over rational function field (say in x). Then x and y are not always the variables X and Y of the coordinate ring of the affine plane. Things are more complicated if the curve is in space (of dim > 2). -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/e86f87d9-8448-4f4e-af0e-1c749b193291n%40googlegroups.com.
