Changes between Initial Version and Version 44 of Ticket #9972

10/18/10 04:41:59 (10 years ago)

I am attaching a patch that does not compute preimage_cones yet, but the rest is claimed to be ready for review/comments. I have removed classes for lattice morphisms themselves since they were not adding anything anymore. All of the old functionality is moved to FanMorphism constructor as you have suggested above. Codomain fan can now be omitted and will be computed, if possible.

This feature has exposed a problem I mentioned (I think) when we were adding warnings to the Fan constructor. The image fan is generated by images of cones of the original fan and these images may coincide or become non-maximal. As a result, one of the doctests fails due to the warning that some cones were discarded and users may see such a message as well, which will be quite confusing, I think. What should we do? Add a parameter to Fan(..., warn=True) and set it to False explicitly in the internal code?

Current queue:

  • trac_9972_add_cone_embedding.patch
  • trac_9972_improve_element_constructors.patch
  • trac_9972_remove_enhanced_cones_and_fans.patch
  • trac_9972_add_fan_morphisms.patch


  • Ticket #9972

    • Property Status changed from new to needs_work
    • Property Cc vbraun added
    • Property Summary changed from Add toric lattice morphisms to Add fan morphisms
    • Property Reviewers changed from to Volker Braun
    • Property Work issues changed from to implement preimage_cones
  • Ticket #9972 – Description

    initial v44  
    1 This patch adds classes for toric lattices homspaces and homomorphisms and allows checking fan compatibility and automatic subdivision to achieve this compatibility.
     1This patch adds a module for fan morphisms - morphisms between lattices with specified fans in the domain and codomain, which are compatible with this morphism. Compatibility check and automatic construction of the codomain fan or refinement of the domain fan are implemented.
    33See #9604 for prerequisites.