diff options
author | Eric Wieser <wieser.eric@gmail.com> | 2018-07-31 00:41:28 -0700 |
---|---|---|
committer | GitHub <noreply@github.com> | 2018-07-31 00:41:28 -0700 |
commit | 7f4579279a6a6aa07df664b901afa36ab3fc5ce0 (patch) | |
tree | 3524c05c661f4948eabf066b46b5ad3aaf6ad617 /numpy/lib/stride_tricks.py | |
parent | 24960daf3e326591047eb099af840da6e95d0910 (diff) | |
parent | 9bb569c4e0e1cf08128179d157bdab10c8706a97 (diff) | |
download | numpy-7f4579279a6a6aa07df664b901afa36ab3fc5ce0.tar.gz |
Merge branch 'master' into ix_-preserve-type
Diffstat (limited to 'numpy/lib/stride_tricks.py')
-rw-r--r-- | numpy/lib/stride_tricks.py | 28 |
1 files changed, 13 insertions, 15 deletions
diff --git a/numpy/lib/stride_tricks.py b/numpy/lib/stride_tricks.py index 545623c38..bc5993802 100644 --- a/numpy/lib/stride_tricks.py +++ b/numpy/lib/stride_tricks.py @@ -100,10 +100,9 @@ def as_strided(x, shape=None, strides=None, subok=False, writeable=True): interface['strides'] = tuple(strides) array = np.asarray(DummyArray(interface, base=x)) - - if array.dtype.fields is None and x.dtype.fields is not None: - # This should only happen if x.dtype is [('', 'Vx')] - array.dtype = x.dtype + # The route via `__interface__` does not preserve structured + # dtypes. Since dtype should remain unchanged, we set it explicitly. + array.dtype = x.dtype view = _maybe_view_as_subclass(x, array) @@ -124,9 +123,12 @@ def _broadcast_to(array, shape, subok, readonly): needs_writeable = not readonly and array.flags.writeable extras = ['reduce_ok'] if needs_writeable else [] op_flag = 'readwrite' if needs_writeable else 'readonly' - broadcast = np.nditer( + it = np.nditer( (array,), flags=['multi_index', 'refs_ok', 'zerosize_ok'] + extras, - op_flags=[op_flag], itershape=shape, order='C').itviews[0] + op_flags=[op_flag], itershape=shape, order='C') + with it: + # never really has writebackifcopy semantics + broadcast = it.itviews[0] result = _maybe_view_as_subclass(array, broadcast) if needs_writeable and not result.flags.writeable: result.flags.writeable = True @@ -217,23 +219,19 @@ def broadcast_arrays(*args, **kwargs): Examples -------- >>> x = np.array([[1,2,3]]) - >>> y = np.array([[1],[2],[3]]) + >>> y = np.array([[4],[5]]) >>> np.broadcast_arrays(x, y) [array([[1, 2, 3], - [1, 2, 3], - [1, 2, 3]]), array([[1, 1, 1], - [2, 2, 2], - [3, 3, 3]])] + [1, 2, 3]]), array([[4, 4, 4], + [5, 5, 5]])] Here is a useful idiom for getting contiguous copies instead of non-contiguous views. >>> [np.array(a) for a in np.broadcast_arrays(x, y)] [array([[1, 2, 3], - [1, 2, 3], - [1, 2, 3]]), array([[1, 1, 1], - [2, 2, 2], - [3, 3, 3]])] + [1, 2, 3]]), array([[4, 4, 4], + [5, 5, 5]])] """ # nditer is not used here to avoid the limit of 32 arrays. |