Robert Kern <robert.kern@gmail.com> wrote:
Michael McNeil Forbes wrote:
What are the semantics of the "take" function?
I would have expected that the following have the same shape and size:
a = array([1,2,3]) inds = a.nonzero() a[inds] array([1, 2, 3]) a.take(inds) array([[1, 2, 3]])
Is there a bug somewhere here or is this intentional?
It's a result of a.nonzero() returning a tuple. ... __getitem__ interprets tuples specially: a[1,2,3] == a[(1,2,3)], also a[0,] == a[0].
.take() doesn't; it simply tries to convert its argument into an array. It can convert (array([0, 1, 2]),) into array([[0, 1, 2]]), so it does.
Okay. I understand why this happens from the code. 1) Is there a design reason for this inconsistent treatment of "indices"? 2) If so, is there some place (perhaps on the Wiki or in some source code I cannot find) that design decisions like this are discussed? (I have several other inconsistencies I would like to address, but would like to find out if they are "intentional" before wasting people's time.) Thanks, Michael.