tf.keras.losses.KLDivergence

Computes Kullback-Leibler divergence loss between y_true and y_pred.

loss = y_true * log(y_true / y_pred)

See: https://en.wikipedia.org/wiki/Kullback%E2%80%93Leibler_divergence

Standalone usage:

y_true = [[0, 1], [0, 0]]
y_pred = [[0.6, 0.4], [0.4, 0.6]]
# Using 'auto'/'sum_over_batch_size' reduction type.
kl = tf.keras.losses.KLDivergence()
kl(y_true, y_pred).numpy()
0.458
# Calling with 'sample_weight'.
kl(y_true, y_pred, sample_weight=[0.8, 0.2]).numpy()
0.366
# Using 'sum' reduction type.
kl = tf.keras.losses.KLDivergence(
    reduction=tf.keras.losses.Reduction.SUM)
kl(y_true, y_pred).numpy()
0.916
# Using 'none' reduction type.
kl = tf.keras.losses.KLDivergence(
    reduction=tf.keras.losses.Reduction.NONE)
kl(y_true, y_pred).numpy()
array([0.916, -3.08e-06], dtype=float32)

Usage with the compile() API:

model.compile(optimizer='sgd', loss=tf.keras.losses.KLDivergence())

reduction (Optional) Type of tf.keras.losses.Reduction to apply to loss. Default value is AUTO. AUTO indicates that the reduction option will be determined by the usage context. For almost all cases this defaults to SUM_OVER_BATCH_SIZE. When used with tf.distribute.Strategy, outside of built-in training loops such as tf.keras compile and fit, using AUTO or SUM_OVER_BATCH_SIZE will raise an error. Please see this custom training tutorial for more details.
name Optional name for the op. Defaults to 'kl_divergence'.

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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Returns the config dictionary for a Loss instance.