mindspore.ops.avg_pool2d

mindspore.ops.avg_pool2d(x, kernel_size=1, strides=1, pad_mode='valid', data_format='NCHW')[source]

Average pooling operation.

Applies a 2D average pooling over an input Tensor which can be regarded as a composition of 2D input planes. Typically the input is of shape \((N_{in}, C_{in}, H_{in}, W_{in})\), outputs regional average in the \((H_{in}, W_{in})\)-dimension. Given kernel size \((k_{h}, k_{w})\) and strides , the operation is as follows.

\[\text{output}(N_i, C_j, h, w) = \frac{1}{k_{h} * k_{w}} \sum_{m=0}^{k_{h}-1} \sum_{n=0}^{k_{w}-1} \text{input}(N_i, C_j, strides[0] \times h + m, strides[1] \times w + n)\]

Warning

  • Global pooling is supported.

  • For Ascend, the height of kernel_size and the weight of kernel_size are positive integers within the range [1, 255]. ksize_h * ksize_w < 256.

  • For Ascend, due to instruction restrictions, the values of ‘strides_h’ and ‘strides_w’ are positive integers within the range [1, 63].

Parameters

  • x (Tensor) – Tensor of shape \((N, C_{in}, H_{in}, W_{in})\).

  • kernel_size (Union[int, tuple[int]]) – The size of kernel used to take the average value. It is an int number that represents height and width of the kernel, or a tuple of two int numbers that represent height and width respectively. Default: 1.

  • strides (Union[int, tuple[int]]) – The distance of kernel moving, an int number that represents the height and width of movement are both strides, or a tuple of two int numbers that represent height and width of movement respectively. Default: 1.

  • pad_mode (str) –

    The optional value for pad mode, is ‘same’ or ‘valid’. Default: ‘valid’.

    • same: The height and width of the output are the same as the input divided by ‘strides’ and rounded up.

    • valid: Returns the output of the valid calculation without filling. Redundant pixels that do not satisfy the calculation will be discarded.

  • data_format (str) – The format of input and output data. It should be ‘NHWC’ or ‘NCHW’. Default: ‘NCHW’.

Returns

Tensor, with shape \((N, C_{out}, H_{out}, W_{out})\).

Raises

  • TypeError – If kernel_size or strides is neither int nor tuple.

  • ValueError – If kernel_size or strides is less than 1.

  • ValueError – If pad_mode is neither ‘valid’ nor ‘same’ with not case sensitive.

  • ValueError – If data_format is neither ‘NCHW’ nor ‘NHWC’.

  • ValueError – If length of shape of x is not equal to 4.

Supported Platforms:

Ascend GPU CPU

Examples

>>> x = Tensor(np.arange(1 * 3 * 3 * 4).reshape(1, 3, 3, 4), mindspore.float32)
>>> output = ops.avg_pool2d(x, kernel_size=2, strides=1, pad_mode='VALID')
>>> print(output)
[[[[ 2.5   3.5   4.5]
   [ 6.5   7.5   8.5]]
  [[14.5  15.5  16.5]
   [18.5  19.5  20.5]]
  [[26.5  27.5  28.5]
   [30.5  31.5  32.5]]]]