# megengine.functional.mean¶

mean(inp, axis=None, keepdims=False)[源代码]

Calculates the mean of tensor elements over a given axis (or axes).

Tensor

if the mean was computed over the entire tensor, a zero-dimensional tensor containing the mean; otherwise, a non-zero-dimensional tensor containing the means. The returned tensor must have a data type determined by 类型提升规则.

Special Cases

Let N equal the number of elements over which to compute the mean.

• If N is 0, the mean is NaN.

• If $$x_i$$ is NaN, the mean is NaN (i.e., NaN values propagate).

>>> F.mean(Tensor([1, 2, 3]))
Tensor(2.0, device=xpux:0)

>>> import numpy as np
>>> F.mean(Tensor([1, np.nan, 3]))
Tensor(nan, device=xpux:0)


Along an axis:

>>> F.mean(Tensor([[1, 2, 3], [4, 5, 6]]), axis=0)
Tensor([2.5 3.5 4.5], device=xpux:0)
>>> F.mean(Tensor([[1, 2, 3], [4, 5, 6]]), axis=1)
Tensor([2. 5.], device=xpux:0)