oneflow.nn.functional.sparse_softmax_cross_entropy

oneflow.nn.functional.sparse_softmax_cross_entropy(labels, logits)

The interface is consistent with TensorFlow. The documentation is referenced from: https://www.tensorflow.org/api_docs/python/tf/nn/sparse_softmax_cross_entropy_with_logits

Computes sparse softmax cross entropy between logits and labels.

Measures the probability error in discrete classification tasks in which the classes are mutually exclusive (each entry is in exactly one class). For example, each CIFAR-10 image is labeled with one and only one label: an image can be a dog or a truck, but not both.

A common use case is to have logits of shape [batch_size, num_classes] and have labels of shape [batch_size], but higher dimensions are supported, in which case the dim-th dimension is assumed to be of size num_classes. logits must have the dtype of float16, float32, or float64, and labels must have the dtype of int32 or int64.

Parameters

  • labels (Tensor) – shape with [d_0, d_1, …, d_{r-1}] (where r is rank of labels and output) and dtype int32 or int64. Each entry in labels must be an index in [0, num_classes).

  • logits (Tensor) – Per-label activations (typically a linear output) of shape [d_0, d_1, …, d_{r-1}, num_classes] and dtype float16, float32, or float64. These activation energies are interpreted as unnormalized log probabilities.

Returns

A Tensor of the same shape as labels and of the same type as logits with the softmax cross entropy loss.

Return type

output (Tensor)

Examples::
>>> import numpy as np
>>> import oneflow as flow
>>> np_logits = np.array(
...      [
...          [2.0, -5.0, 0.5, -0.1],
...          [0.0, 0.0, 1.9, 1.4],
...          [-100.0, 100.0, -100.0, -100.0],
...      ]
...  )
>>> np_labels = np.array([0, 3, 1])
>>> logits = flow.tensor(np_logits, dtype=flow.float32)
>>> labels = flow.tensor(np_labels, dtype=flow.int32)
>>> output = flow.nn.functional.sparse_softmax_cross_entropy(
...     labels=labels, logits=logits
... )
>>> output
tensor([ 2.9751e-01,  1.1448e+00, -1.4305e-06], dtype=oneflow.float32)