On Wed, Mar 13, 2013 at 6:56 AM, Matt U <mpuec...@mit.edu> wrote: > Is it possible to create a numpy array which points to the same data in a > different numpy array (but in different order etc)?
You can do this (easily), but only if the "different order" can be defined in terms of strides. A simple example is a transpose: In [3]: a = np.arange(12).reshape((3,4)) In [4]: a Out[4]: array([[ 0, 1, 2, 3], [ 4, 5, 6, 7], [ 8, 9, 10, 11]]) In [5]: b = a.T In [6]: b Out[6]: array([[ 0, 4, 8], [ 1, 5, 9], [ 2, 6, 10], [ 3, 7, 11]]) # b is the transpose of a # but a view on the same data block: # change a: In [7]: a[2,1] = 44 In [8]: a Out[8]: array([[ 0, 1, 2, 3], [ 4, 5, 6, 7], [ 8, 44, 10, 11]]) # b is changed, too. In [9]: b Out[9]: array([[ 0, 4, 8], [ 1, 5, 44], [ 2, 6, 10], [ 3, 7, 11]]) check out "stride tricks" for clever things you can do. But numpy does require that the data in your array be a contiguous block, in order, so you can't arbitrarily re-arrange it while keeping a view. HTH, -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception chris.bar...@noaa.gov _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion