not really, at least not that i'm aware of. you should ask this at numpy/scipy since they are much more similar to matlab ... (these libraries are part of sage) basically, python is slower in some respect, e.g. loops, since they involve much more complex objects (i.e. python objects!). on the other hand, it is much easier to include compiled code which makes them much faster (see cython for near C speed loops, that's another project, also part of sage and a lot is built using it) one other basic difference is, that since numpy uses python objects, you pass references to functions - not an entire copy as with matlab. consequently, function calls are faster and use less memory (there are also "views", which represent a smaller part of a matrix - modifications in a view show up in the real matrix) python data structures are more complex and flexible, for example, you can choose how the vectors are aligned in memory (column vs. rows). that's cute if you want to speed up certain operations. also, there are projects aimed to "replace" matlab based on python, look at pythonxy, enthought suite, spyder ( http://code.google.com/p/spyderlib/ ), ...
one direct example i can give you: sage/python with numpy: sage: m = random_matrix(RDF, 1000) # random_matrix is sage code and different from randn # to archieve the same, do: from numpy import random m = random.randn(1000) sage: from numpy.linalg import svd sage: %time U,s,Vh = svd(m.numpy()) MATLAB 2009a s = 1000; m = randn(s,s); tic; [u,s,v] = svd(m); toc background of this story: lapack/double/dgesvd.f vs. lapack/double/ dgesdd.f in netlib.org so, bottom line, it's not really a question of sage vs. matlab since you have to look into specific python tools to archive the same. sage includes some of them and a future task is to wrap them "directly" in sage specific functions. H --~--~---------~--~----~------------~-------~--~----~ 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 URL: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
