openvino/docs/ops/sparse/EmbeddingSegmentsSum_3.md

# EmbeddingSegmentsSum {#openvino_docs_ops_sparse_EmbeddingSegmentsSum_3}

**Versioned name**: *EmbeddingSegmentsSum-3*

**Category**: *Sparse*

**Short description**: Computes sums of segments of embeddings, without instantiating the intermediate embeddings.

**Detailed description**: This is [sparse.segment_sum](https://www.tensorflow.org/api_docs/python/tf/sparse/segment_sum) operation from Tensorflow. For each index in `indices` this operator gets values from `data` embedding table and sums all values belonging to each segment. Values in `segment_ids` define which segment index in `indices` tensor belong to, e.g. `segments_ids` with value `[0,0,0,1,1,3,5,5]` define 4 non empty segments other segments are empty, the number of segments is defined by `num_segments` input.

**Attributes**: EmbeddingSegmentsSum operation has no attributes.

**Inputs**:

*   **1**: `emb_table` tensor containing the embedding lookup table of the module of shape `[num_emb, emb_dim1, emb_dim2, ...]` and of type *T*. **Required.**

*   **2**: `indices` tensor of shape `[num_indices]` and of type *T_IND*. **Required.**

*   **3**: `segment_ids` tensor of shape `[num_indices]` and of type *T_IND* with indices into the output Tensor. Values should be sorted and can be repeated. **Required.**

*   **4**: `num_segments` scalar of type *T_IND* indicating the number of segments. **Required.**

*   **5**: `default_index` scalar of type *T_IND* containing default index in embedding table to fill empty segments. If not provided empty segments are filled with zeros. **Optional.**

*   **6**: `per_sample_weights` tensor of the same shape as `indices` and of type *T*. Each value in this tensor are multiplied with each value pooled from embedding table for each index. Optional, default is tensor of ones.

**Outputs**:

*   **1**: tensor of shape `[num_segments, emb_dim1, emb_dim2, ...]` and of type *T* containing embeddings for each bag.

**Types**

* *T*: any numeric type.

* *T_IND*: `int32` or `int64`.

**Example**

```xml
<layer ... type="EmbeddingSegmentsSum" ... >
    <input>
        <port id="0">     <!-- emb_table value is: [[-0.2, -0.6], [-0.1, -0.4], [-1.9, -1.8], [-1.,  1.5], [ 0.8, -0.7]] -->
            <dim>5</dim>
            <dim>2</dim>
        </port>
        <port id="1">     <!-- indices value is: [0, 2, 3, 4] -->
            <dim>4</dim>
        </port>
        <port id="2"/>    <!-- segment_ids value is: [0, 0, 2, 2] - second segment is empty -->
            <dim>4</dim>
        </port>
        <port id="3"/>    <!-- num_segments value is: 3 -->
        <port id="4"/>    <!-- default_index value is: 0 -->
        <port id="5"/>    <!-- per_sample_weigths value is: [0.5, 0.5, 0.5, 0.5] -->
            <dim>4</dim>
        </port>
    </input>
    <output>
        <port id="6">     <!-- output value is: [[-1.05, -1.2], [-0.2, -0.6], [-0.1, 0.4]] -->
            <dim>3</dim>
            <dim>2</dim>
        </port>
    </output>
</layer>
```