[Numpy-discussion] Response to PEP suggestions

Jeff Whitaker jswhit at fastmail.fm
Thu Feb 17 12:14:16 EST 2005

Travis Oliphant wrote:

> 2) Multidimensional array indexing.
> Sometimes it is useful to select out of an array some elements based 
> on it's linear (flattened) index in the array.   MATLAB, for example, 
> will allow you to take a three-dimensional array and index it with a 
> single integer based on it's Fortran-order:  x(1,1,1),  x(2,1,1), ...
> What I'm proposing would have X[K] essentially equivalent to X.flat[K].  

Maybe I'm missing something, but in Numeric and Numarray right now

 >>> from Numeric import *
 >>> a = reshape(arange(9),(3,3))
 >>> print a
[[0 1 2]
 [3 4 5]
 [6 7 8]]
 >>> a[1]
array([3, 4, 5])
 >>> a.flat[1]

so a[K] and a.flat[K] are very different things for multidimensional 
arrays.  I think it would be a bad idea to change this now - it would 
certainly break a lot of my code.

Or are you only talking about the case when K is a rank-1 index array 
and not a scalar?


Jeffrey S. Whitaker         Phone  : (303)497-6313
Meteorologist               FAX    : (303)497-6449
NOAA/OAR/CDC  R/CDC1        Email  : Jeffrey.S.Whitaker at noaa.gov
325 Broadway                Office : Skaggs Research Cntr 1D-124
Boulder, CO, USA 80303-3328 Web    : http://tinyurl.com/5telg

More information about the NumPy-Discussion mailing list