diff --git a/mindspore/ops/operations/nn_ops.py b/mindspore/ops/operations/nn_ops.py index 61d7f2cf4b..59677303e0 100644 --- a/mindspore/ops/operations/nn_ops.py +++ b/mindspore/ops/operations/nn_ops.py @@ -1993,6 +1993,26 @@ class NLLLoss(PrimitiveWithInfer): r""" Gets the negative log likelihood loss between logits and labels. + The nll loss with reduction=none can be described as: + + .. math:: + + \ell(x, t)=L=\left\{l_{1}, \ldots, l_{N}\right\}^{\top}, + \quad l_{n}=-w_{t_{n}} x_{n, t_{n}}, + \quad w_{c}=\text { weight }[c] \cdot 1 + + where x is the input, t is the target. w is the weight. and N is the batch size. c belonging [0, C-1] is + class index, where C is the number of classes. + + If reduction is not 'none' (default 'mean'), then + + .. math:: + + \ell(x, t)=\left\{\begin{array}{ll} + \sum_{n=1}^{N} \frac{1}{\sum_{n=1}^{N} w_{t n}} l_{n}, & \text { if reduction }=\text { 'mean'; } \\ + \sum_{n=1}^{N} l_{n}, & \text { if reduction }=\text { 'sum' } + \end{array}\right. + Args: reduction (string): Apply specific reduction method to the output: 'none', 'mean', 'sum'. Default: "mean". @@ -2000,16 +2020,27 @@ class NLLLoss(PrimitiveWithInfer): - **input** (Tensor) - Input logits, with shape :math:`(N, C)`. Data type only support float32 or float16. - **target** (Tensor) - Ground truth labels, with shape :math:`(N)`. Data type only support int32. - **weight** (Tensor) - The rescaling weight to each class, with shape :math:`(C)` and data type only - support float32 or float16`. + support float32 or float16`. Outputs: - Tuple of 2 tensors composed with `loss` and `total_weight`. when `reduction` is `none` and `input` is 2D - tensor, the `loss` shape is `(N,)`. Otherwise, the `loss` and the `total_weight` is a scalar. The data type - of `loss` and `total_weight` are same with `input's` and `weight's` respectively. + Tuple of 2 tensors composed with `loss` and `total_weight`. + + - **loss** (Tensor) - when `reduction` is `none` and `input` is 2D tensor, the `loss` shape is `(N,)`. + Otherwise, the `loss` is a scalar. The data type is same with `input's`. + - **total_weight** (Tensor) - the `total_weight` is a scalar. The data type is same with `weight's`. + + Raises: + TypeError: If x and weight data type are not float16 or float32 tensor, target data type is not int32 tensor. + ValueError: If x is not a one or two dimension tensor, target and weight not a one dimension tensor. + When x is a two dimension tensor, the first dimension of x is not equal to target, and second + dimension of x is not equal to weight. + When x is a one dimension tensor, the dimensions of x, target and weight should be equal to + each other. Supported Platforms: ``Ascend`` + Examples: >>> input = Tensor(np.array([[0.5488135, 0.71518934], >>> [0.60276335, 0.5448832], @@ -6246,7 +6277,7 @@ class Dropout(PrimitiveWithInfer): class Dropout3d(PrimitiveWithInfer): """ During training, randomly zeroes some of the channels of the input tensor - with probability keep_prob from a Bernoulli distribution. + with probability keep_prob from a Bernoulli distribution. Args: keep_prob (float): The keep probability of a channel, between 0 and 1, e.g. `keep_prob` = 0.8,