On Fri, Mar 5, 2010 at 12:04 AM, Rob Beezer <[email protected]> wrote: > Cayley tables for groups aren't working properly (http:// > trac.sagemath.org/sage_trac/ticket/7340), so I've taken this as an > excuse to write some new code for a more general object I've been > calling an "operation table." (http://trac.sagemath.org/sage_trac/ > ticket/7555) Besides groups, it could be used with lattices, for both > operations in a ring, etc.
I wonder if this could even morph into a pseudo-spreadsheet class? You could attach formulas to certain cells then evaluate them and plot the results using matplotlib? > > Cayley tables are currently matrices over a ring of multivariate > polynomials, where each element of the group is represented by a > different variable. My approach is to simply create tables to look > at, ie ASCII or Latex or colored squares or.... Before I get this all > organized to contribute I could use some advice on two questions: > > 1) Where would you park this? I'd be inclined to stick it in a > misc.py module somewhere since it might be employed in a variety of > places, but I don't even see a natural choice for an existing such > module to add to, nor an obvious place to start a new one. > > 2) It would be unwieldy to place actual elements of, say a > permutation group, into the body of the table. Similar to the > variables mentioned above, I've been representing elements by > "integers" (according to the ordering output by list()), using 0's on > the left to pad to a common width, so elements might look like '03' > and '12'. This runs the risk of being confused with actual integer > elements of a group, ring or lattice in certain situations. However, > I would also like to allow alternate orderings (with keyword > requests), for example, in the presence of a normal subgroup the table > can have a nice block structure if the elements are ordered by > cosets. Any ideas for compact ways to consistently represent elements > of an algebraic structure in such a visual table? > > Thanks, > Rob > > -- > To post to this group, send an email to [email protected] > To unsubscribe from this group, send an email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/sage-devel > URL: http://www.sagemath.org > -- To post to this group, send an email to [email protected] To unsubscribe from this group, send an email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
