# tensorflow::ops::UnsortedSegmentSum

#include <math_ops.h>

Computes the sum along segments of a tensor.

## Summary

Read the section on segmentation for an explanation of segments.

Computes a tensor such that $$output[i] = \sum_{j...} data[j...]$$ where the sum is over tuples j... such that segment_ids[j...] == i. Unlike SegmentSum, segment_ids need not be sorted and need not cover all values in the full range of valid values.

If the sum is empty for a given segment ID i, output[i] = 0. If the given segment ID i is negative, the value is dropped and will not be added to the sum of the segment.

num_segments should equal the number of distinct segment IDs.

Caution: On CPU, values in segment_ids are always validated to be less than num_segments, and an error is thrown for out-of-bound indices. On GPU, this does not throw an error for out-of-bound indices. On Gpu, out-of-bound indices result in safe but unspecified behavior, which may include ignoring out-of-bound indices or outputting a tensor with a 0 stored in the first dimension of its shape if num_segments is 0.

c = [[1,2,3,4], [5,6,7,8], [4,3,2,1]] tf.math.unsorted_segment_sum(c, [0, 1, 0], num_segments=2).numpy() array([[5, 5, 5, 5], [5, 6, 7, 8]], dtype=int32)

Args:

• scope: A Scope object
• segment_ids: A tensor whose shape is a prefix of data.shape. The values must be less than num_segments.

Caution: The values are always validated to be in range on CPU, never validated on GPU.

Returns:

• Output: Has same shape as data, except for the first segment_ids.rank dimensions, which are replaced with a single dimension which has size num_segments.

### Constructors and Destructors

UnsortedSegmentSum(const ::tensorflow::Scope & scope, ::tensorflow::Input data, ::tensorflow::Input segment_ids, ::tensorflow::Input num_segments)

### Public attributes

operation
Operation
output
::tensorflow::Output

### Public functions

node() const
::tensorflow::Node *
operator::tensorflow::Input() const
operator::tensorflow::Output() const

## Public attributes

### operation

Operation operation

### output

::tensorflow::Output output

## Public functions

### UnsortedSegmentSum

 UnsortedSegmentSum(
const ::tensorflow::Scope & scope,
::tensorflow::Input data,
::tensorflow::Input segment_ids,
::tensorflow::Input num_segments
)

### node

::tensorflow::Node * node() const

### operator::tensorflow::Input

 operator::tensorflow::Input() const

### operator::tensorflow::Output

 operator::tensorflow::Output() const
[]
[]