Re: [Numpy-discussion] Arrays of Python Values
Hi, I've converted all of the code to use record arrays, for a 10-fold speed boost. Thanks, Ian ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] Arrays of Python Values
Fri, 23 Jul 2010 01:16:41 -0700, Ian Mallett wrote: [clip] Because I've never used arrays of Python objects (and Googling didn't turn up any examples), I'm stuck on how to sort the corresponding array in NumPy in the same way. I doubt you will gain any speed by switching from Python lists to Numpy arrays containing Python objects. Of course, perhaps I'm just trying something that's absolutely impossible, or there's an obviously better way. I get the feeling that having no Python objects in the NumPy array would speed things up even more, but I couldn't figure out how I'd handle the different attributes (or specifically, how to keep them together during a sort). What're my options? One option could be to use structured arrays to store the data, instead of Python objects. -- Pauli Virtanen ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] Arrays of Python Values
On Friday 23 July 2010 10:16:41 Ian Mallett wrote: self.patches.sort( lambda x,y:cmp(x.residual_radiance,y.residual_radiance), reverse=True ) Using sort(key = lambda x: x.residual_radiance) should be faster. Because I've never used arrays of Python objects (and Googling didn't turn up any examples), I'm stuck on how to sort the corresponding array in NumPy in the same way. Of course, perhaps I'm just trying something that's absolutely impossible, or there's an obviously better way. I get the feeling that having no Python objects in the NumPy array would speed things up even more, but [...] Exactly. Maybe you can use record arrays? (Have a look at complex dtypes, i.e. struct-like dtypes for arrays.) Never tried sort on these, but I'd hope that's possible. HTH, Hans ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
