# tensorflow::ops::SegmentSum

`#include <math_ops.h>`

Computes the sum along segments of a tensor.

## Summary

Read [the section on segmentation](https://tensorflow.org/api_docs/python/tf/math#Segmentation) for an explanation of segments.

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

If the sum is empty for a given segment ID `i`, `output[i] = 0`.


![](https://www.tensorflow.org/static/versions/r2.0/api_docs/cc/images/SegmentSum.png)

<br />

For example:


```
c = tf.constant([[1,2,3,4], [4, 3, 2, 1], [5,6,7,8]])
tf.segment_sum(c, tf.constant([0, 0, 1]))
# ==> [[5, 5, 5, 5],
#      [5, 6, 7, 8]]
```

<br />

Arguments:

- scope: A [Scope](https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/scope#classtensorflow_1_1_scope) object
- segment_ids: A 1-D tensor whose size is equal to the size of `data`'s first dimension. Values should be sorted and can be repeated.

<br />

Returns:

- `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/output#classtensorflow_1_1_output`: Has same shape as data, except for dimension 0 which has size `k`, the number of segments.

<br />

| ### Constructors and Destructors ||
|---|---|
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/segment-sum#classtensorflow_1_1ops_1_1_segment_sum_1a4f3c70df95d8be6a28060d01172358b5(const ::https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/scope#classtensorflow_1_1_scope & scope, ::https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/input#classtensorflow_1_1_input data, ::https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/input#classtensorflow_1_1_input segment_ids)` ||

| ### Public attributes ||
|---|---|
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/segment-sum#classtensorflow_1_1ops_1_1_segment_sum_1a2a06a8d703c2aaac86320935d50be188` | `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/operation#classtensorflow_1_1_operation` |
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/segment-sum#classtensorflow_1_1ops_1_1_segment_sum_1a475eb3ccf98c3aa9097ae79ad39b06ac` | `::https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/output#classtensorflow_1_1_output` |

| ### Public functions ||
|---|---|
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/segment-sum#classtensorflow_1_1ops_1_1_segment_sum_1a02ad69e7aabc1982f43a6f669d6dd884() const ` | `::tensorflow::Node *` |
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/segment-sum#classtensorflow_1_1ops_1_1_segment_sum_1ab999a101c40c98e2574092d55e877ec2() const ` | ` `` ` |
| `https://www.tensorflow.org/versions/r2.0/api_docs/cc/class/tensorflow/ops/segment-sum#classtensorflow_1_1ops_1_1_segment_sum_1af298372906f96c26410a5edaeb58a2e4() const ` | ` `` ` |

## Public attributes

### operation

```
Operation operation
```

### output

```
::tensorflow::Output output
```

## Public functions

### SegmentSum

```
 SegmentSum(
  const ::tensorflow::Scope & scope,
  ::tensorflow::Input data,
  ::tensorflow::Input segment_ids
)
```

### node

```
::tensorflow::Node * node() const 
```

### operator::tensorflow::Input

```
 operator::tensorflow::Input() const 
```

### operator::tensorflow::Output

```
 operator::tensorflow::Output() const 
```