On Wednesday 04 October 2006 10:13, Tim Hochberg wrote: > Sebastian Haase wrote: > > Quick question hopefully somewhat related to this: > > Does numexpr fully support float32 arrays ? > > I don't recall. At one point there was a tentative plan to support > float32 by casting them a block at a time to float64, operating on them > and them casting them back. That's to limit the number of bytecodes that > we need to support and keep the switch statement at a manageable size. > However, it doesn't look like that ever got implemented, so the answer > is probably no. > > -tim
Does that mean its considered "impratical" to ever add native float32 support ? Is the switch-statement you mention written by hand or is that automatically generated ? -Sebastian > > > -Sebastian > > > > On Wednesday 04 October 2006 09:32, Tim Hochberg wrote: > >> Ivan Vilata i Balaguer wrote: > >>> It seemed that discontiguous arrays worked OK in Numexpr since r1977 or > >>> so, but I have come across some alignment or striding problems which > >>> can be seen with the following code:: > >>> > >>> import numpy > >>> import numexpr > >>> > >>> array_length = 10 > >>> array_descr = [('c1', numpy.int32), ('c2', numpy.uint16)] > >>> > >>> array = numpy.empty((array_length,), dtype=array_descr) > >>> for i in xrange(array_length): > >>> array['c1'][i] = i > >>> array['c2'][i] = 0xaaaa > >>> > >>> print numexpr.evaluate('c1', {'c1': array['c1']}) > >>> print numexpr.evaluate('c1', {'c1': array['c1'].copy()}) > >>> > >>> Im my computer, Pentium IV with NumPy 1.0rc1 and Numexpr r2239 > >>> (unmodified) this gives the following result:: > >>> > >>> [ 0 109226 -1431699456 2 240298 > >>> -1431699456 4 371370 8 633514] > >>> [0 1 2 3 4 5 6 7 8 9] > >>> > >>> The test works right when ``evaluate()`` is used with 'c2' instead of > >>> 'c1', and also when 'c2' also measures 32 bits and fields are aligned. > >>> Maybe the ``memsteps`` value is not getting used somewhere. Any ideas > >>> on this? > >> > >> I suspect that there are some assumptions that the element separation > >> is an integral multiple of the element size. I certainly didn't have > >> record arrays in mind when I was working on the striding stuff, so it > >> wouldn't surprise me. This should be fixed: preferably to do the right > >> thing and at a minimum to cleanly raise an exception rather than > >> spitting out garbage. I don't know that I'll have time to mess with it > >> soon though. > >> > >> -tim > >> > >> > >> ------------------------------------------------------------------------ > >>- Take Surveys. Earn Cash. Influence the Future of IT > >> Join SourceForge.net's Techsay panel and you'll get the chance to share > >> your opinions on IT & business topics through brief surveys -- and earn > >> cash > >> http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDE > >>V _______________________________________________ > >> Numpy-discussion mailing list > >> Numpy-discussion@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/numpy-discussion > > > > ------------------------------------------------------------------------- > > Take Surveys. Earn Cash. Influence the Future of IT > > Join SourceForge.net's Techsay panel and you'll get the chance to share > > your opinions on IT & business topics through brief surveys -- and earn > > cash > > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > > _______________________________________________ > > Numpy-discussion mailing list > > Numpy-discussion@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/numpy-discussion > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share > your opinions on IT & business topics through brief surveys -- and earn > cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ > Numpy-discussion mailing list > Numpy-discussion@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/numpy-discussion ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Numpy-discussion mailing list Numpy-discussion@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/numpy-discussion