David Cournapeau wrote: > Christopher Barker wrote: >> My real question is what compiler and library writers are doing -- has >> anyone (OK, I guess MS and gcc are all I care about anyway) built >> anything optimized for them? Are they going to dump them? Who knows? > What do you mean by optimization ?
Well, I'm quite specifically not being precise about that. It appears the POINT of valarray was to provide a way to do computation that compiler(library) writers could optimize in various ways for the system at hand. The one example I have seen is someone that wrote a version that takes advantage of the PPC altivec instructions: (http://www.pixelglow.com/stories/altivec-valarray-2/) Anyway, at this point I'm far less concerned about optimization that just a more robust and convenient way to deal with data that raw pointers. > I > remember having used blitz at some point, and I thought it was terrible. Darn -- it looks so promising. > I think C++ is much more useful > for the automatic memory management through RAII, which is what > std::vector gives you. and std::valarray not? I guess where I'm at now is deciding if there is any advantage or disadvantage to using std::valarray vs. std::vector. The other option is to go with something else: boost::multiarray, blitz++, etc. However, at least in term of how well they might p;lay with numpy arrays, I don't see a reason to do so. > If your compiler supports restrict, use it > (http://www.cellperformance.com/mike_acton/2006/05/demystifying_the_restrict_keyw.html), > Thanks for that link -- I'll keep that in mind. And now I finally think I understand what is meant by "aliased" pointer - which explains why, quite deliberately, you can't create a valarray from an existing pointer to a data block. > The fact that, while C++ being a popular language, a standard class for > matrix algebra does not exist yet shows me that this is not that useful, > or too complicate to develop. Could be. Personally, I'm not looking for matrix algebra, rather a generic nd-array class - but the argument is the same. -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception [EMAIL PROTECTED] _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
