Combines (nests of) input elements into a dataset of (nests of) windows.
tf.raw_ops.WindowDataset( input_dataset, size, shift, stride, drop_remainder, output_types, output_shapes, name=None )
A "window" is a finite dataset of flat elements of size size
(or possibly fewer if there are not enough input elements to fill the window and drop_remainder
evaluates to false).
The shift
argument determines the number of input elements by which the window moves on each iteration. The first element in the k
th window will be element
1 + (k-1) * shift
of the input dataset. In particular, the first element of the first window will always be the first element of the input dataset.
If the stride
parameter is greater than 1, then each window will skip (stride - 1)
input elements between each element that appears in the window. Output windows will still contain size
elements regardless of the value of stride
.
The stride
argument determines the stride of the input elements, and the shift
argument determines the shift of the window.
For example, letting {...}
to represent a Dataset:
tf.data.Dataset.range(7).window(2)
produces { {0, 1}, {2, 3}, {4, 5}, {6} }
tf.data.Dataset.range(7).window(3, 2, 1, True)
produces { {0, 1, 2}, {2, 3, 4}, {4, 5, 6} }
tf.data.Dataset.range(7).window(3, 1, 2, True)
produces { {0, 2, 4}, {1, 3, 5}, {2, 4, 6} }
Note that when the window
transformation is applied to a dataset of nested elements, it produces a dataset of nested windows.
tf.data.Dataset.from_tensor_slices((range(4), range(4))).window(2)
produces {({0, 1}, {0, 1}), ({2, 3}, {2, 3})}
tf.data.Dataset.from_tensor_slices({"a": range(4)}).window(2)
produces { {"a": {0, 1} }, {"a": {2, 3} } }
Args | |
---|---|
input_dataset | A Tensor of type variant . |
size | A Tensor of type int64 . An integer scalar, representing the number of elements of the input dataset to combine into a window. Must be positive. |
shift | A Tensor of type int64 . An integer scalar, representing the number of input elements by which the window moves in each iteration. Defaults to size . Must be positive. |
stride | A Tensor of type int64 . An integer scalar, representing the stride of the input elements in the sliding window. Must be positive. The default value of 1 means "retain every input element". |
drop_remainder | A Tensor of type bool . A Boolean scalar, representing whether the last window should be dropped if its size is smaller than window_size . |
output_types | A list of tf.DTypes that has length >= 1 . |
output_shapes | A list of shapes (each a tf.TensorShape or list of ints ) that has length >= 1 . |
name | A name for the operation (optional). |
Returns | |
---|---|
A Tensor of type variant . |
© 2020 The TensorFlow Authors. All rights reserved.
Licensed under the Creative Commons Attribution License 3.0.
Code samples licensed under the Apache 2.0 License.
https://www.tensorflow.org/versions/r2.3/api_docs/python/tf/raw_ops/WindowDataset