On Sat, Mar 5, 2011 at 9:28 AM, Ralf Gommers <ralf.gomm...@googlemail.com> wrote: > On Sat, Mar 5, 2011 at 8:09 AM, Russell E. Owen <ro...@uw.edu> wrote: >> The page <http://docs.scipy.org/doc/numpy/user/basics.rec.html> >> >> gives a good introduction to structured arrays. However, it says nothing >> about how to set a particular element (all fields at once) from a >> collection of data. >> >> For instance: >> >> stArr = numpy.zeros([4,5], dtype=[("pos", float, (2,)), ("rot", float)]) >> >> The question is how to set stArr[0]? >> >> >From experimentation it appears that you can provide a tuple, but not a >> list. Hence the following works just fine (and that the tuple can >> contain a list): >> strArr[0,0] = ([1.0, 1.1], 2.0) >> >> but the following fails: >> strArr[0,0] = [[1.0, 1.1], 2.0] >> with an error: >> TypeError: expected a readable buffer object >> >> This is useful information if one is trying to initialize a structured >> array from a collection of data, such as that returned from a database >> query. >>
I added a bit at the end here, though it is mentioned briefly above. Feel free to expand. It's a wiki. You just need edit rights. http://docs.scipy.org/numpy/docs/numpy.doc.structured_arrays/ > I'm wondering if that's not a bug? If it's intentional then it is > certainly counterintuitive. > This comes up from time to time. http://thread.gmane.org/gmane.comp.python.numeric.general/30793/focus=30793 Perhaps an enhancement ticket could be filed? It doesn't sound trivial to implement. Skipper _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
