The most pressing problem in sage at the moment seems to be that presently there only seem to be morphisms between schemes. You need rational maps for this (especially from a singular model, the map to a canonical model might only be a rational map).
"SchemeMorphism" in Sage is a map defined by rational functions between schemes. It does not check the domain of definition. Hence it represent mathematically rational maps rather than morphisms. I guess that the "morphism" in "SchemeMorphism" was intended to mean morphism in category theory rather than morphisms in scheme theory. I might be overlooking something ... currently sage allows for the construction of a rational map P2 -> P2, but then asking for the image of a curve C in P2 leads to TypeError: map must be a morphism (which should probably be a ValueError). Perhaps the code is just unnecessarily picky? What is your code? -- 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/4f4a4f2b-1b51-4650-85e4-4ef2444247e5n%40googlegroups.com.
