index_fill

paddle. index_fill ( x: Tensor, index: Tensor, axis: int, value: float, name: str | None = None ) [source]

Fill the elements of the input tensor with value by the specific axis and index.

As shown below, a [3, 3] 2D tensor is updated via the index_fill operation. With axis=0, index=[0, 2] and value=-1, the 1st and 3rd row elements become -1. The resulting tensor, still [3, 3], has updated values.

Illustration of Case 2
Parameters

  • x (Tensor) – The Destination Tensor. Supported data types are int32, int64, float16, float32, float64.

  • index (Tensor) – The 1-D Tensor containing the indices to index. The data type of index must be int32 or int64.

  • axis (int) – The dimension along which to index.

  • value (int|float) – The tensor used to fill with.

  • name (str|None, optional) – For details, please refer to Name. Generally, no setting is required. Default: None.

Returns

Tensor, same dimension and dtype with x.

Examples

>>> import paddle
>>> input_tensor = paddle.to_tensor([[1, 2, 3], [4, 5, 6], [7, 8, 9]], dtype='int64')
>>> index = paddle.to_tensor([0, 2], dtype="int32")
>>> value = -1
>>> res = paddle.index_fill(input_tensor, index, 0, value)
>>> print(input_tensor)
Tensor(shape=[3, 3], dtype=int64, place=Place(gpu:0), stop_gradient=True,
       [[1, 2, 3],
        [4, 5, 6],
        [7, 8, 9]])
>>> print(res)
Tensor(shape=[3, 3], dtype=int64, place=Place(gpu:0), stop_gradient=True,
       [[-1, -1, -1],
        [ 4,  5,  6],
        [-1, -1, -1]])