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tf.unique
Finds unique elements in a 1-D tensor.
tf.unique(
    x, out_idx=tf.dtypes.int32, name=None
)
  This operation returns a tensor y containing all of the unique elements of x sorted in the same order that they occur in x; x does not need to be sorted. This operation also returns a tensor idx the same size as x that contains the index of each value of x in the unique output y. In other words:
y[idx[i]] = x[i] for i in [0, 1,...,rank(x) - 1]
Examples:
# tensor 'x' is [1, 1, 2, 4, 4, 4, 7, 8, 8]
y, idx = unique(x)
y ==> [1, 2, 4, 7, 8]
idx ==> [0, 0, 1, 2, 2, 2, 3, 4, 4]
  # tensor 'x' is [4, 5, 1, 2, 3, 3, 4, 5]
y, idx = unique(x)
y ==> [4, 5, 1, 2, 3]
idx ==> [0, 1, 2, 3, 4, 4, 0, 1]
  | Args | |
|---|---|
x | 
      A Tensor. 1-D. | 
     
out_idx | 
      An optional tf.DType from: tf.int32, tf.int64. Defaults to tf.int32. | 
     
name | 
      A name for the operation (optional). | 
| Returns | |
|---|---|
A tuple of Tensor objects (y, idx). | 
     |
y | 
      A Tensor. Has the same type as x. | 
     
idx | 
      A Tensor of type out_idx. | 
     
© 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/unique