tf.raw_ops.SegmentMaxV2

Computes the maximum along segments of a tensor.

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Compat aliases for migration

See Migration guide for more details.

tf.compat.v1.raw_ops.SegmentMaxV2

tf.raw_ops.SegmentMaxV2(
    data, segment_ids, num_segments, name=None
)

Read the section on segmentation for an explanation of segments.

Computes a tensor such that \(output_i = \max_j(data_j)\) where max is over j such that segment_ids[j] == i.

If the maximum is empty for a given segment ID i, it outputs the smallest possible value for the specific numeric type, output[i] = numeric_limits<T>::lowest().

Note: That this op is currently only supported with jit_compile=True.

Caution: On CPU, values in segment_ids are always validated to be sorted, and an error is thrown for indices that are not increasing. On GPU, this does not throw an error for unsorted indices. On GPU, out-of-order indices result in safe but unspecified behavior, which may include treating out-of-order indices as the same as a smaller following index.

The only difference with SegmentMax is the additional input num_segments. This helps in evaluating the output shape in compile time. num_segments should be consistent with segment_ids. e.g. Max(segment_ids) should be equal to num_segments - 1 for a 1-d segment_ids With inconsistent num_segments, the op still runs. only difference is, the output takes the size of num_segments irrespective of size of segment_ids and data. for num_segments less than expected output size, the last elements are ignored for num_segments more than the expected output size, last elements are assigned smallest possible value for the specific numeric type.

For example:

@tf.function(jit_compile=True)
def test(c):
  return tf.raw_ops.SegmentMaxV2(data=c, segment_ids=tf.constant([0, 0, 1]), num_segments=2)
c = tf.constant([[1,2,3,4], [4, 3, 2, 1], [5,6,7,8]])
test(c).numpy()
array([[4, 3, 3, 4],
       [5, 6, 7, 8]], dtype=int32)

Args
data	A Tensor. Must be one of the following types: float32, float64, int32, uint8, int16, int8, int64, bfloat16, uint16, half, uint32, uint64.
segment_ids	A Tensor. Must be one of the following types: int32, int64. A 1-D tensor whose size is equal to the size of data's first dimension. Values should be sorted and can be repeated. The values must be less than num_segments. Caution: The values are always validated to be sorted on CPU, never validated on GPU.
num_segments	A Tensor. Must be one of the following types: int32, int64.
name	A name for the operation (optional).

Returns
A Tensor. Has the same type as data.