On Thu, Jan 26, 2012 at 10:13 AM, Robert Bradshaw <[email protected]> wrote: > To get a quick sense of what people think about this, I've decided to > rephrase this as a survey. To be clear, though this coincides with > Matlab syntax, the intent is not to try to make Sage a Matlab clone, > rather it is to add a missing feature to Sage. > > Should [a, b; c, d] be a valid syntax for matrix construction in Sage? >
[X ] Yes, I love this syntax! It would be make life better for me and my students. > [ ] I wouldn't oppose, but may require some convincing. > [ ] No, that's a horrible idea. > > Why? > > > Should the default basering be more linear-algebra friendly? E.g. R -> > Frac(R), RR -> RDF. > > [ ] Yes, that would take away a lot of pain/be what I'd have to > specify manually anyway. > [ ] Could be handy, but the drawbacks are significant. [X] No, matrices over QQ are for sissies, real mathematicians work over ZZ unless otherwise specified. I'm more for *consistency* between the matrix command the matrix notation and for fixing any issues with matrices over ZZ that make them "bad". -- William > > Why? > > > > On Thu, Jan 26, 2012 at 6:12 AM, Jason Grout > <[email protected]> wrote: >> On 1/26/12 7:54 AM, Marco Streng wrote: >>> >>> 2012/1/26 Jason Grout<[email protected]>: >>>> >>>> That's part of the problem pointed out in an earlier message---our RR >>>> matrices really are pretty bad for numerical things, but RDF matrices are >>>> the way to go (the RDF matrices use standard numerical algorithms for the >>>> most part, whereas RR matrices use naive algorithms that can be really >>>> bad >>>> and slow). This should be fixed, but for right now, RR matrices don't >>>> seem >>>> to be all that useful compared to RDF matrices. >>> >>> >>> Is RDF always better than 53-bit RR in this way? If so, perhaps >>> "RealNumber" or the preparser could be changed to use RDF if the >>> precision is sufficiently small. Most users typing 12.345 will want >>> the fastest implementation and not something generic. >> >> >> No, this is a linear algebra problem, not a general problem in Sage. Usually >> RR is better mathematically than RDF. >> >> Thanks, >> >> Jason >> >> >> >> >> -- >> 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 -- William Stein Professor of Mathematics University of Washington http://wstein.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
