summaryrefslogtreecommitdiff
path: root/doc/source
diff options
context:
space:
mode:
authorPauli Virtanen <pav@iki.fi>2016-09-11 19:30:25 +0200
committerPauli Virtanen <pav@iki.fi>2017-01-19 22:12:47 +0100
commitf55932a21849d230b39f7f5ced354863756bf6d5 (patch)
treee6ee49c4ff944b9b96ec238c794fbb2487d622ab /doc/source
parent0bff7b30466b26963cf4fc1b280eb207b74e9851 (diff)
downloadnumpy-f55932a21849d230b39f7f5ced354863756bf6d5.tar.gz
BUG: umath: in reduceat, arrays must be copied on overlap even if they are the same
Diffstat (limited to 'doc/source')
-rw-r--r--doc/source/reference/c-api.iterator.rst12
1 files changed, 11 insertions, 1 deletions
diff --git a/doc/source/reference/c-api.iterator.rst b/doc/source/reference/c-api.iterator.rst
index b5d00f4be..5761e56c2 100644
--- a/doc/source/reference/c-api.iterator.rst
+++ b/doc/source/reference/c-api.iterator.rst
@@ -474,7 +474,8 @@ Construction and Destruction
via *different* index/dtype/shape combinations.
- In particular, unless the arrays have the same shape, dtype,
- strides, and start address, any shared common data byte accessible
+ strides, start address, and NPY_ITER_OVERLAP_NOT_SAME is not specified,
+ any shared common data byte accessible
by indexing implies overlap.
Because exact overlap detection has exponential runtime
@@ -618,6 +619,15 @@ Construction and Destruction
returns true from the corresponding element in the ARRAYMASK
operand.
+ .. c:var:: NPY_ITER_OVERLAP_NOT_SAME
+
+ In the memory overlap checks done when ``NPY_ITER_COPY_IF_OVERLAP``
+ is specified, consider this array as overlapping even if it is
+ exactly the same as another array.
+
+ This flag should be set on arrays that are not accessed in the
+ iterator order.
+
.. c:function:: NpyIter* NpyIter_AdvancedNew(npy_intp nop, PyArrayObject** op, npy_uint32 flags, NPY_ORDER order, NPY_CASTING casting, npy_uint32* op_flags, PyArray_Descr** op_dtypes, int oa_ndim, int** op_axes, npy_intp* itershape, npy_intp buffersize)
Extends :c:func:`NpyIter_MultiNew` with several advanced options providing