Hi, Trying to work with WeylGroups I noticed that the notions of roots differ depending on whether implementation='matrix' or implementation='permutation'. I think it would be good if they didn't or at least if there was an error instead of nonsensical output.
Here is an example: L = RootSystem(['A',3]) root_space = L.root_space() root_to_ambient = root_space.to_ambient_space_morphism() alpha = root_to_ambient(root_space.simple_roots()[1]) W = WeylGroup(L, implementation='matrix') g = W[1] print(alpha) print(g.action(alpha)) The outputs are (1, -1, 0, 0) and (0, -1, 0, 1). So far everything is as expected. Now if I replace W by the 'permutation'-version (which I had hoped to work as a drop-in replacement) W = WeylGroup(L, implementation='permutation') g = W[1] print(g.action(alpha)) print(W.roots()[0]) the outputs are (1, -1, -1) and (1, 0, 0). What's a little annoying is that the root systems use different ambient spaces. What's extremely annoying is that g.action(alpha) accepts a 4-touple without raising an exception. Is there a plan of making the behavior more coherent or should one never switch between the two implementations? Best, Stefan -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
