I would like to propose the addition of a matrix literal syntax, namely sage: [1, 2; 3, 4] [1 2] [3 4] sage: [1, 2; 3, 4] * [5, 6; 7, 8] [19 22] [43 50]
Currently one must write sage: matrix([[1, 2], [3, 4]]) [1 2] [3 4] sage: matrix([[1, 2], [3, 4]]) * matrix([[5, 6], [7, 8]]) [19 22] [43 50] This is a followup from the discussion at https://groups.google.com/forum/#!msg/sage-devel/p-nrpKUBMm8/LUMAfoXsz-UJ , but brought to the forefront due to a wanting to publish something with many small matrices as examples. Not all the details need be fleshed out, but the basic idea is that a semi-colon in within brackets would create a matrix (row). Nested matrices, trailing semicolons, spanning lines, etc. would of course be supported correctly and is not that hard of a challenge. Of course adding to the preparser should not be done lightly, but I think this is simple, useful, and intuitive enough to justify the diversion from pure Python. At this point I'm just looking for an up/down vote on whether we could count on something like this to go in, though more detailed design decision would be interesting as well. Preliminary patch at http://trac.sagemath.org/sage_trac/ticket/12354 . A second question, what of the basering? Lots of times it's more convenient to use the fraction field, especially if there was an easier way to set it "back" to ZZ for those who care about the it. One could go a step further and create matrices over RDF if the entries are in RR (as linear algebra over RR is both slow and bad). One of the main complaints I've heard about Sage from non (pure) mathematicians is that they feel that the abstract notions of rings, etc. are shoved in their face, and having to specify QQ every time an matrix is constructed falls into this... Thoughts? - Robert -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
