On Thu, Jan 15, 2009 at 4:26 PM, William Stein <wst...@gmail.com> wrote: > On Thu, Jan 15, 2009 at 3:12 PM, Jason Grout > <jason-s...@creativetrax.com> wrote: >> >> c mullan wrote: >>> Hi, >>> >>> Suppose I compute the Jordan Normal Form of a matrix, >>> >>> A.jordan_form() >>> >>> Then in the output I can see that the block sizes are indicated (by >>> subdivide='True'), but I can't extract this information. I would like >>> a list of block sizes, (e.g. [2,2,1,1,1] for a 7x7 matrix). >>> >>> I cannot figure out how to do this, any ideas? >>> >> >> >> sage: a = matrix(ZZ,4,[1, 0, 0, 0, 0, 1, 0, 0, 1, -1, 1, 0, 1, -1, 1, 2]) >> sage: b=a.jordan_form() >> sage: b >> >> [2|0 0|0] >> [-+---+-] >> [0|1 1|0] >> [0|0 1|0] >> [-+---+-] >> [0|0 0|1] >> sage: b.subdivisions >> ([0, 1, 3, 4], [0, 1, 3, 4]) > > I just have to comment: > > sage: b.subdivisions = 10 > sage: b.subdivisions > 10 > > Notice that you can make the subdivisions nonsense because it can be changed. > Also, of course, > sage: b.subdivisions? > ... The Integer class represents arbitrary precision > integers. It derives from the Element class, so > [other useless stuff] > > I don't like that at all either. I wish that subdivisions were a > method with a proper docstring, doctests, etc., and that variable were > hidden. > > Then one would do: > sage: b.subdivisions? > useful stuff (and also it would be in the reference manual) > and > sage: b.subdivisions() > ([0, 1, 3, 4], [0, 1, 3, 4]) > > > One could argue that throughout Sage maybe we should use attributes > for properties and function calls much less. However, there's no > hundreds of thousands of lines of code, and it mostly uses the > "b.subdivisions() style" instead of the "b.subdivisions" style, so for > consistency at this point, I think we should just stick to that. > > Thoughts? >
OH, this is now trac # 4983: http://trac.sagemath.org/sage_trac/ticket/4983 William --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
