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Diffstat (limited to 'numpy/doc/indexing.py')
| -rw-r--r-- | numpy/doc/indexing.py | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/numpy/doc/indexing.py b/numpy/doc/indexing.py index d3f442c21..9e9f0a10c 100644 --- a/numpy/doc/indexing.py +++ b/numpy/doc/indexing.py @@ -1,5 +1,4 @@ -""" -============== +"""============== Array indexing ============== @@ -50,7 +49,7 @@ than dimensions, one gets a subdimensional array. For example: :: That is, each index specified selects the array corresponding to the rest of the dimensions selected. In the above example, choosing 0 -means that remaining dimension of lenth 5 is being left unspecified, +means that the remaining dimension of length 5 is being left unspecified, and that what is returned is an array of that dimensionality and size. It must be noted that the returned array is not a copy of the original, but points to the same values in memory as does the original array. @@ -62,7 +61,7 @@ element being returned. That is: :: 2 So note that ``x[0,2] = x[0][2]`` though the second case is more -inefficient a new temporary array is created after the first index +inefficient as a new temporary array is created after the first index that is subsequently indexed by 2. Note to those used to IDL or Fortran memory order as it relates to @@ -229,10 +228,13 @@ most straightforward case, the boolean array has the same shape: :: >>> y[b] array([21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34]) -The result is a 1-D array containing all the elements in the indexed -array corresponding to all the true elements in the boolean array. As -with index arrays, what is returned is a copy of the data, not a view -as one gets with slices. +Unlike in the case of integer index arrays, in the boolean case, the +result is a 1-D array containing all the elements in the indexed array +corresponding to all the true elements in the boolean array. The +elements in the indexed array are always iterated and returned in +:term:`row-major` (C-style) order. The result is also identical to +``y[np.nonzero(b)]``. As with index arrays, what is returned is a copy +of the data, not a view as one gets with slices. The result will be multidimensional if y has more dimensions than b. For example: :: |