Re: [Numpy-discussion] sort method raises unexpected error with axis=None
Ah, To answer my own question: Suggestion 1: Wrap the .sort method call in a tiny python wrapper of the form: def sort(self, axis=-1, kind='quicksort', order=None): if axis=None: _c_sort(self.ravel(), axis, kind, order) else: _c_sort(self, axis, kind, order) I guess this is not good because self.ravel might return a copy, in situations I don't think I fully grasp? Guessing that there is no other way to do a guaranteed inplace sort for axis=None, I guess that making that clear in the method docstring is the best way to go? Matthew ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] sort method raises unexpected error with axis=None
Hi, Is it possible, in fact, to do an inplace sort on an array with axis=None (ie flat sort)? Should the sort method have its docstring changed to reflect the fact that axis=None is not valid? Sorry to press on, but it would be good to resolve this somehow. Is there some reason not to: Suggestion 1: Wrap the .sort method call in a tiny python wrapper of the form: def sort(self, axis=-1, kind='quicksort', order=None): if axis=None: _c_sort(self.ravel(), axis, kind, order) else: _c_sort(self, axis, kind, order) or 2: Modify the method docstring to remove axis=None as valid option. I'm happy to do either. Matthew ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] sort method raises unexpected error with axis=None
On Feb 13, 2008 1:52 PM, Matthew Brett [EMAIL PROTECTED] wrote: Ah, To answer my own question: Suggestion 1: Wrap the .sort method call in a tiny python wrapper of the form: def sort(self, axis=-1, kind='quicksort', order=None): if axis=None: _c_sort(self.ravel(), axis, kind, order) else: _c_sort(self, axis, kind, order) I guess this is not good because self.ravel might return a copy, in situations I don't think I fully grasp? Guessing that there is no other way to do a guaranteed inplace sort for axis=None, I guess that making that clear in the method docstring is the best way to go? I think it is possible to make sort work with the None keyword, So I think the question is whether or not we want it to. If we do, then the current lack is a bug, if we don't, then the documentation needs to be fixed. Chuck ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] sort method raises unexpected error with axis=None
On 12/02/2008, Matthew Brett [EMAIL PROTECTED] wrote: Is it possible, in fact, to do an inplace sort on an array with axis=None (ie flat sort)? It is, sometimes; just make an array object to point to the flattened version and sort that: In [16]: b = a[:] In [17]: b.shape = (16,) In [18]: b.sort() This is not always possible, depending on the arrangement of a in memory. An efficient way to handle in-place (or out-of-place, come to think of it) median along multiple axes is actually to take medians along all axes in succession. That saves you some sorting effort, and some programming effort, and doesn't require in-place multidimensional sorting: In [24]: def all_axes_median(a): : if len(a.shape)1: : return all_axes_median(N.median(a)) : else: : return N.median(a) : : In [26]: all_axes_median(N.reshape(N.arange(32),(2,4,2,-1))) Out[26]: 15.5 Anne ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] sort method raises unexpected error with axis=None
On 12/02/2008, Anne Archibald [EMAIL PROTECTED] wrote: An efficient way to handle in-place (or out-of-place, come to think of it) median along multiple axes is actually to take medians along all axes in succession. That saves you some sorting effort, and some programming effort, and doesn't require in-place multidimensional sorting: Aargh. Sorry. No, that doesn't work: In [28]: all_axes_median(N.reshape([1,5,6,7],(2,2))) Out[28]: 4.75 Oops. Anne ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
Re: [Numpy-discussion] sort method raises unexpected error with axis=None
Hi, To rephrase: Is it possible, in fact, to do an inplace sort on an array with axis=None (ie flat sort)? Should the sort method have its docstring changed to reflect the fact that axis=None is not valid? Matthew On Feb 10, 2008 7:50 PM, Matthew Brett [EMAIL PROTECTED] wrote: Hi, I just noticed this: From the sort method docstring: axis : integer Axis to be sorted along. None indicates that the flattened array should be used. Default is -1. In [40]: import numpy as N In [41]: a = N.arange(10) In [42]: N.sort(a, None) Out[42]: array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]) In [43]: a.sort(None) --- TypeError Traceback (most recent call last) /home/mb312/ipython console in module() TypeError: an integer is required Perhaps the sort method is calling the c code directly, and this is not checking for axis=None? Matthew ___ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
