count_nonzero

paddle. count_nonzero ( x: Tensor, axis: int | Sequence[int] | None = None, keepdim: bool = False, name: str | None = None ) → Tensor [source]

Counts the number of non-zero values in the tensor x along the specified axis.

Parameters

  • x (Tensor) – An N-D Tensor, the data type is bool, float16, float32, float64, int32 or int64.

  • axis (int|list|tuple, optional) – The dimensions along which the sum is performed. If None, sum all elements of x and return a Tensor with a single element, otherwise must be in the range \([-rank(x), rank(x))\). If \(axis[i] < 0\), the dimension to reduce is \(rank + axis[i]\).

  • keepdim (bool, optional) – Whether to reserve the reduced dimension in the output Tensor. The result Tensor will have one fewer dimension than the x unless keepdim is true, default value is False.

  • name (str|None, optional) – Name for the operation (optional, default is None). For more information, please refer to api_guide_Name.

Returns

Results of count operation on the specified axis of input Tensor x, it’s data type is ‘int64’.

Return type

Tensor

Examples

>>> import paddle
>>> # x is a 2-D Tensor:
>>> x = paddle.to_tensor([[0., 1.1, 1.2], [0., 0., 1.3], [0., 0., 0.]])
>>> out1 = paddle.count_nonzero(x)
>>> out1
Tensor(shape=[], dtype=int64, place=Place(cpu), stop_gradient=True,
3)
>>> out2 = paddle.count_nonzero(x, axis=0)
>>> out2
Tensor(shape=[3], dtype=int64, place=Place(cpu), stop_gradient=True,
[0, 1, 2])
>>> out3 = paddle.count_nonzero(x, axis=0, keepdim=True)
>>> out3
Tensor(shape=[1, 3], dtype=int64, place=Place(cpu), stop_gradient=True,
[[0, 1, 2]])
>>> out4 = paddle.count_nonzero(x, axis=1)
>>> out4
Tensor(shape=[3], dtype=int64, place=Place(cpu), stop_gradient=True,
[2, 1, 0])
>>> out5 = paddle.count_nonzero(x, axis=1, keepdim=True)
>>> out5
Tensor(shape=[3, 1], dtype=int64, place=Place(cpu), stop_gradient=True,
[[2],
 [1],
 [0]])

>>> # y is a 3-D Tensor:
>>> y = paddle.to_tensor([[[0., 1.1, 1.2], [0., 0., 1.3], [0., 0., 0.]],
...                         [[0., 2.5, 2.6], [0., 0., 2.4], [2.1, 2.2, 2.3]]])
>>> out6 = paddle.count_nonzero(y, axis=[1, 2])
>>> out6
Tensor(shape=[2], dtype=int64, place=Place(cpu), stop_gradient=True,
[3, 6])
>>> out7 = paddle.count_nonzero(y, axis=[0, 1])
>>> out7
Tensor(shape=[3], dtype=int64, place=Place(cpu), stop_gradient=True,
[1, 3, 5])