SliceScatter#

Versioned name: SliceScatter-15

Category: Data movement

Short description: Creates copy of data tensor and applies elements from updates using slicing parametrized by start, stop and step over axes dimensions.

Detailed description:

The operation produces a copy of data tensor and updates it using values specified by updates at specific slices parametrized by start, stop and step values over corresponding axes dimensions. The output shape and type is the same as data. Number of elements for start, stop, step and axes is required to be equal. Values in axes are required to be unique.

Operator SliceScatter-15 is an equivalent to following NumPy snippet:

def slice_scatter_15(
    data: np.ndarray,
    updates: np.ndarray,
    start: List[int],
    stop: List[int],
    step: List[int],
    axes: Optional[List[int]] = None,
):
    out = np.copy(data)
    if axes is None:
        axes = list(range(len(start)))
    slice_list = [slice(None)] * data.ndim
    for slice_start, slice_stop, slice_step, slice_axis in zip(start, stop, step, axes):
        slice_list[slice_axis] = slice(slice_start, slice_stop, slice_step)
    out[tuple(slice_list)] = updates
    return out

Attributes: SliceScatter does not have attributes.

Inputs:

1: data tensor of arbitrary rank r >= 1 and of type T. Required.
2: updates - tensor of type T and same shape as data except axes set by axes where dimensions should be equal to the length of corresponding update slices. Required.
3: start - 1D tensor of type T_IND.

Defines the starting coordinate of the update slice in the data tensor at axes dimension. A negative index value represents counting elements from the end of that dimension. A value larger than the size of a dimension is silently clamped. Required.
4: stop - 1D tensor of type T_IND.

Defines the coordinate of the opposite vertex of the update slice, or where the update slice ends. Stop indexes are exclusive, which means values lying on the ending edge are not updated. A value larger than the size of a dimension is silently clamped. To create slice to the end of a dimension of unknown size INT_MAX may be used (or INT_MIN if slicing backwards). Required.
5: step - 1D tensor of type T_IND.

Integer value that specifies the increment between each index used in slicing. Value cannot be 0, negative value indicates slicing backwards. Required.
6: axes - 1D tensor of type T_AXIS.

Optional 1D tensor indicating which dimensions the values in start, stop and step apply to. Negative value means counting dimensions from the end. The range is [-r, r - 1], where r is the rank of the data input tensor. Values are required to be unique. Default value: [0, 1, 2, ..., start.shape[0] - 1]. Optional.

Number of elements in start, stop, step, and axes inputs are required to be equal.

Outputs:

1: tensor with shape equal to data tensor of the type T.

Types

T: any numeric type.
T_IND: any supported integer type.
T_AXIS: any supported integer type.

Example

Example 1: Fill slice over axis==0.

<layer ... type="SliceScatter">
    <input>
        <port id="0" precision="FP32">  <!-- data -->
            <dim>2</dim>
            <dim>5</dim>  <!-- values: [[0, 1, 2, 3, 4], [5, 6, 7, 8, 9]] -->
        </port>
        <port id="1" precision="FP32">  <!-- updates -->
            <dim>1</dim>
            <dim>5</dim>  <!-- values: [[10, 20, 30, 40, 50]] -->
        </port>
        <port id="2" precision="I32">  <!-- start -->
            <dim>1</dim>  <!-- values: [0] -->
        </port>
        <port id="3" precision="I32">  <!-- stop -->
            <dim>1</dim>  <!-- values: [1] -->
        </port>
        <port id="4" precision="I32">  <!-- step -->
            <dim>1</dim>  <!-- values: [1] -->
        </port>
        <port id="5" precision="I32">  <!-- axes -->
            <dim>1</dim>  <!-- values: [0] -->
        </port>
    </input>
    <output>
        <port id="6" precision="FP32">
            <dim>2</dim>
            <dim>5</dim>  <!-- values: [[10, 20, 30, 40, 50], [5, 6, 7, 8, 9]] -->
        </port>
    </output>
</layer>

Example 2: Update every second value over axis==1, clamp values of start and stop.

<layer ... type="SliceScatter">
    <input>
        <port id="0" precision="FP32">  <!-- data -->
            <dim>2</dim>
            <dim>5</dim>  <!-- values: [[0, 1, 2, 3, 4], [5, 6, 7, 8, 9]] -->
        </port>
        <port id="1" precision="FP32">  <!-- updates -->
            <dim>2</dim>
            <dim>3</dim>  <!-- values: [[10, 20, 30], [40, 50, 60]] -->
        </port>
        <port id="2" precision="I32">  <!-- start -->
            <dim>1</dim>  <!-- values: [-25], silently clamped to 0 -->
        </port>
        <port id="3" precision="I32">  <!-- stop -->
            <dim>1</dim>  <!-- values: [25], silently clamped to 5 -->
        </port>
        <port id="4" precision="I32">  <!-- step -->
            <dim>1</dim>  <!-- values: [2] -->
        </port>
        <port id="5" precision="I32">  <!-- axes -->
            <dim>1</dim>  <!-- values: [1] -->
        </port>
    </input>
    <output>
        <port id="6" precision="FP32">
            <dim>2</dim>
            <dim>5</dim>  <!-- values: [[10, 1, 20, 3, 30], [40, 6, 50, 8, 60]] -->
        </port>
    </output>
</layer>

Example 3: Update every second value over both axes with different slice starts.

<layer ... type="SliceScatter">
    <input>
        <port id="0" precision="FP32">  <!-- data -->
            <dim>3</dim>
            <dim>5</dim>  <!-- values: [[0, 1, 2, 3, 4], [5, 6, 7, 8, 9], [10, 11, 12, 13, 14]] -->
        </port>
        <port id="1" precision="FP32">  <!-- updates -->
            <dim>2</dim>
            <dim>2</dim>  <!-- values: [[50, 60], [70, 80]] -->
        </port>
        <port id="2" precision="I32">  <!-- start -->
            <dim>1</dim>  <!-- values: [0, 1] -->
        </port>
        <port id="3" precision="I32">  <!-- stop -->
            <dim>1</dim>  <!-- values: [3, 5] -->
        </port>
        <port id="4" precision="I32">  <!-- step -->
            <dim>1</dim>  <!-- values: [2, 2] -->
        </port>
    </input>
    <output>
        <port id="5" precision="FP32">
            <dim>3</dim>
            <dim>5</dim>  <!-- values: [[0, 50, 2, 60, 4], [5, 6, 7, 8, 9], [10, 70, 12, 80, 14]] -->
        </port>
    </output>
</layer>