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]

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).

A tuple of Tensor objects (y, idx).
y A Tensor. Has the same type as x.
idx A Tensor of type out_idx.