# tf.math.unsorted_segment_mean

|---|---|
| [![](https://www.tensorflow.org/images/tf_logo_32px.png) TensorFlow 2 version](https://www.tensorflow.org/api_docs/python/tf/math/unsorted_segment_mean) | [![](https://www.tensorflow.org/images/GitHub-Mark-32px.png) View source on GitHub](https://github.com/tensorflow/tensorflow/blob/v1.15.0/tensorflow/python/ops/math_ops.py#L3516-L3559) |

Computes the mean along segments of a tensor.

#### View aliases


**Main aliases**

\`tf.unsorted_segment_mean\`
**Compat aliases for migration**

See
[Migration guide](https://www.tensorflow.org/guide/migrate) for
more details.

[`tf.compat.v1.math.unsorted_segment_mean`](https://www.tensorflow.org/api_docs/python/tf/math/unsorted_segment_mean), [`tf.compat.v1.unsorted_segment_mean`](https://www.tensorflow.org/api_docs/python/tf/math/unsorted_segment_mean), \`tf.compat.v2.math.unsorted_segment_mean\`

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    tf.math.unsorted_segment_mean(
        data, segment_ids, num_segments, name=None
    )

Read [the section on
segmentation](https://www.tensorflow.org/versions/r2.0/api_docs/python/tf/math#about_segmentation)
for an explanation of segments.

This operator is similar to the unsorted segment sum operator found
[here](https://www.tensorflow.org/versions/r1.15/api_docs/api_docs/python/math_ops#UnsortedSegmentSum).
Instead of computing the sum over segments, it computes the mean of all
entries belonging to a segment such that:

\\(output_i = 1/N_i \\sum_{j...} data\[j...\]\\) where the sum is over tuples
`j...` such that `segment_ids[j...] == i` with \\N_i\\ being the number of
occurrences of id \\i\\.

If there is no entry for a given segment ID `i`, it outputs 0.

If the given segment ID `i` is negative, the value is dropped and will not
be added to the sum of the segment.

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| ## Args ||
|---|---|
| `data` | A `Tensor` with floating point or complex dtype. |
| `segment_ids` | An integer tensor whose shape is a prefix of `data.shape`. |
| `num_segments` | An integer scalar `Tensor`. The number of distinct segment IDs. |
| `name` | A name for the operation (optional). |

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| ## Returns ||
|---|---|
| A `Tensor`. 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`. ||

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