tf.keras.losses.Poisson

TensorFlow 2 version View source on GitHub

Computes the Poisson loss between y_true and y_pred.

loss = y_pred - y_true * log(y_pred)

Usage:

p = tf.keras.losses.Poisson()
loss = p([1., 9., 2.], [4., 8., 12.])
print('Loss: ', loss.numpy())  # Loss: -0.35702705

Usage with the compile API:

model = tf.keras.Model(inputs, outputs)
model.compile('sgd', loss=tf.keras.losses.Poisson())

Methods

from_config

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Instantiates a Loss from its config (output of get_config()).

Args
config Output of get_config().

Returns
A Loss instance.

get_config

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__call__

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Invokes the Loss instance.

Args
y_true Ground truth values. shape = [batch_size, d0, .. dN]
y_pred The predicted values. shape = [batch_size, d0, .. dN]
sample_weight Optional sample_weight acts as a coefficient for the loss. If a scalar is provided, then the loss is simply scaled by the given value. If sample_weight is a tensor of size [batch_size], then the total loss for each sample of the batch is rescaled by the corresponding element in the sample_weight vector. If the shape of sample_weight is [batch_size, d0, .. dN-1] (or can be broadcasted to this shape), then each loss element of y_pred is scaled by the corresponding value of sample_weight. (Note ondN-1: all loss functions reduce by 1 dimension, usually axis=-1.)

Returns
Weighted loss float Tensor. If reduction is NONE, this has shape [batch_size, d0, .. dN-1]; otherwise, it is scalar. (Note dN-1 because all loss functions reduce by 1 dimension, usually axis=-1.)

Raises
ValueError If the shape of sample_weight is invalid.