summaryrefslogtreecommitdiff
path: root/numpy/add_newdocs.py
diff options
context:
space:
mode:
authorJay Bourque <jay.bourque@continuum.io>2013-07-27 12:45:37 -0500
committerJay Bourque <jay.bourque@continuum.io>2013-08-16 16:39:33 -0500
commit79bc97caa1bd23919ba8cb63850e12cbf5097b97 (patch)
treeac581e73ae097e654464e81b76e7ffb33f7b1a9b /numpy/add_newdocs.py
parent336151e810904277f227584eadc2de119a1a5ac6 (diff)
downloadnumpy-79bc97caa1bd23919ba8cb63850e12cbf5097b97.tar.gz
Update docs
Diffstat (limited to 'numpy/add_newdocs.py')
-rw-r--r--numpy/add_newdocs.py42
1 files changed, 24 insertions, 18 deletions
diff --git a/numpy/add_newdocs.py b/numpy/add_newdocs.py
index e630ae921..ba5e11f21 100644
--- a/numpy/add_newdocs.py
+++ b/numpy/add_newdocs.py
@@ -5819,44 +5819,50 @@ add_newdoc('numpy.core', 'ufunc', ('at',
"""
at(a, indices, b=None)
- Performs operation in place on array for items specified by indices.
- For addition ufunc, this method is equivalent to a[indices] += b,
- except that results are accumulated for indices listed more than once.
- This solves the problem with a[indices] += b where each time a duplicate
- index is encounted, the increment is performed on the original element.
- As a result, an element that appears three times in the fancy indexing
- list will only be incremented once in the final result, whereas with the
- new 'at' method the original element will be incremented by three in the
- final result.
+ Performs unbuffered in place operation on operand 'a' for elements
+ specified by 'indices'. For addition ufunc, this method is equivalent to
+ `a[indices] += b`, except that results are accumulated for elements that
+ are indexed more than once. For example, `a[[0,0]] += 1` will only
+ increment the first element once because of buffering, whereas
+ `add.at(a, [0,0], 1)` will increment the first element twice.
Parameters
----------
a : array_like
- The array to act on.
- indices : array_like
- Paired indices, comma separated (not colon), specifying slices to
- reduce.
- b : array_like or scalar
- Second operation for ufuncs requiring two operands.
+ The array to perform in place operation on.
+ indices : array_like or tuple
+ Array like index object or slice object for indexing into first
+ operand. If first operand has multiple dimensions, indices can be a
+ tuple of array like index objects or slice objects.
+ b : array_like
+ Second operand for ufuncs requiring two operands. Operand must be
+ broadcastable over first operand after indexing or slicing.
Examples
--------
Set items 0 and 1 to their negative values:
- np.negative.at(a, [0, 1])
+ >>> a = np.array([1, 2, 3, 4])
+ >>> np.negative.at(a, [0, 1])
+ array([-1, -2, 3, 4])
::
Increment items 0 and 1, and increment item 2 twice:
- np.add.at(a, [0, 1, 2, 2], 1)
+ >>> a = np.array([1, 2, 3, 4])
+ >>> np.add.at(a, [0, 1, 2, 2], 1)
+ array([2, 3, 5, 4])
::
Add items 0 and 1 in first array to second array,
and store results in first array:
- np.add.at(a, [0, 1], b)
+ >>> a = np.array([1, 2, 3, 4])
+ >>> b = np.array([1, 2])
+ >>> np.add.at(a, [0, 1], b)
+ array([2, 4, 3, 4])
"""))