On Feb 13, 2008 10:56 AM, Francesc Altet <[EMAIL PROTECTED]> wrote: > A Wednesday 13 February 2008, Charles R Harris escrigué: > > OK, > > > > The new quicksorts are in svn. Francesc, can you check them out? > > > > Looks good here. However, you seem to keep using your own copy_string() > instead of plain memcpy(). In previous benchmarks, I've seen that > copy_string() is faster than memcpy only for small values of the length > of the block to be copied. >
Yes, I noticed that your benchmark program crossed over to using memcpy at 16 chars, and I will probably add that feature. I was being conservative to start with. <snip> > Finally, you also will have noticed the indirect sort line in the plot. > This is because I was curious about when this method would win a direct > sort. And, by looking at the plot, it seems that the crosspoint is > around strings of 128 bytes (much more in fact that I initially > thought), and starts to be very significant (around 40% faster) at 256 > bytes. So perhaps it would make sense to add the possibility to choose > the indirect method when sorting those large strings. This, of course, > would require more memory for the indices, but using 4 or 8 additional > bytes (depending if we on 32-bit or 64-bit), when each string takes 200 > bytes, doesn't seem too crazy. In any case, it would be nice to > document this in docstrings. > It would be easy to add this feature, but for the moment I think the best thing is to document it. Another fairly easy change that could be made is to support strided arrays. That might speed sorting of non-contiguous arrays and sorts on axis other than -1. The only reason it isn't there now is that I originally wrote the sorting routines for numarray and numarray's upper level interface passed contiguous arrays to the sort functions. > Be warned, I'd like to stress out that these are my figures for my _own > laptop_. It would be nice if you can verify all of this with other > achitectures (your Core2 machine seems different enough). I can run > the benchmarks on Windows (installed in the same laptop) too. Tell me > if you are interested on me doing this. > Its easy enough to test if you compile from svn, just add your new copy function and change the name in this line: #copy=copy_string, copy_ucs4# to use your function instead of copy_string. Chuck
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