It is NOT possible to multiply two matrices in less than O(n^2) simply because there are n^2 elements, and you got to "touch" all of them at least once!
Rakib On 12/10/10, Luciano Junior <luciano....@gmail.com> wrote: > Dave, thank You very much for yours information. Really, I want to > know a theorical big-O algorithm, mainly to interact with sparce > matrix. We see every day a new technic computation growing world > information, but I not seen a new and revolutionary multiply matrix > algorithm that take less than O(n^2). Maby this not will exists, but > how can we use a parallel programming skills to better to make that > rotine ? Is this what I should like to know. > > 2010/12/8 Dave <dave_and_da...@juno.com>: >> Are you interested in actual computation speed or are you interested >> in theoretical big-O speed? If you want the fastest computation for a >> specific, reasonable-sized problem with no particular structure (i.e., >> non-sparse), then using the ordinary matrix multiply algorithm that is >> coded the best will probably beat any theoretically-faster algorithm. >> You probably will find the fastest matrix-multiplication code in one >> of the sets of the so-called Basic Linear Algebra Subprograms (BLAS). >> Check out http://www.netlib.org/blas/faq.html, and especially 5) >> therein: http://www.netlib.org/blas/faq.html#5. >> >> Dave >> >> On Dec 8, 6:09 am, Luciano Junior <luciano....@gmail.com> wrote: >>> What is best multiply matrix algorithm for: >>> >>> -multiply a n x n matrix by another n x n matrix >>> -multiply a m x n matrix by a n x p matrix >>> >>> I need a best performance cpu algorithm. >>> Note: it can use a parallel programming concept. >>> >>> Thankfully. >>> ---------------------------------------- >>> Luciano. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Algorithm Geeks" group. >> To post to this group, send email to algoge...@googlegroups.com. >> To unsubscribe from this group, send email to >> algogeeks+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/algogeeks?hl=en. >> >> > > > > -- > ---------------------------------------- > Luciano Soares Pinheiro Jr. > Analista desenvolvedor Sr. > > -- > You received this message because you are subscribed to the Google Groups > "Algorithm Geeks" group. > To post to this group, send email to algoge...@googlegroups.com. > To unsubscribe from this group, send email to > algogeeks+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/algogeeks?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
