[NumPy-Tickets] [NumPy] #1535: numpy.random.permutations fails for non-integer arguments

[NumPy Trac]

#1535: numpy.random.permutations fails for non-integer arguments
------------------------------------+---------------------------------------
 Reporter:  robince                 |       Owner:  somebody
     Type:  defect                  |      Status:  new     
 Priority:  normal                  |   Milestone:  2.0.0   
Component:  numpy.random            |     Version:          
 Keywords:  permutation long 64bit  |  
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 When calling numpy.random.permutation with non-integer arguments it fails
 with a cryptic error message:

 {{{
 In [49]: np.random.permutation(12)
 Out[49]: array([10,  9,  4,  7,  3,  8,  0,  6,  5,  1, 11,  2])

 In [50]: np.random.permutation(12.0)
 ---------------------------------------------------------------------------
 TypeError                                 Traceback (most recent call
 last)

 D:\robin\pyentropy-0.4.0\<ipython console> in <module>()

 C:\Python26\lib\site-packages\numpy\random\mtrand.pyd in
 mtrand.RandomState.permutation (build\scons\numpy\random\mtrand
 \mtrand.c:18669)()

 C:\Python26\lib\site-packages\numpy\random\mtrand.pyd in
 mtrand.RandomState.shuffle (build\scons\numpy\random\mtrand\mtr
 and.c:18261)()

 TypeError: len() of unsized object
 > d:\robin\pyentropy-0.4.0\mtrand.pyx(4174)mtrand.RandomState.shuffle
 (build\scons\numpy\random\mtrand\mtrand.c:18261)()
 }}}

 This also happens with long arguments, and so
 np.random.permutation(X.shape[0]) where X is an array fails on 64 bit
 windows (where shape is a tuple of longs).

 It would be great if it could cast to integer or at least raise a proper
 error for non-integer types.

-- 
Ticket URL: <http://projects.scipy.org/numpy/ticket/1535>
NumPy <http://projects.scipy.org/numpy>
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