Model loss functions

loss_mean_squared_error(y_true, y_pred)

loss_mean_absolute_error(y_true, y_pred)

loss_mean_absolute_percentage_error(y_true, y_pred)

loss_mean_squared_logarithmic_error(y_true, y_pred)

loss_squared_hinge(y_true, y_pred)

loss_hinge(y_true, y_pred)

loss_categorical_hinge(y_true, y_pred)

loss_logcosh(y_true, y_pred)

loss_categorical_crossentropy(y_true, y_pred)

loss_sparse_categorical_crossentropy(y_true, y_pred)

loss_binary_crossentropy(y_true, y_pred)

loss_kullback_leibler_divergence(y_true, y_pred)

loss_poisson(y_true, y_pred)

loss_cosine_proximity(y_true, y_pred)

Arguments

y_true

True labels (Tensor)

y_pred

Predictions (Tensor of the same shape as y_true)

Details

Loss functions are to be supplied in the loss parameter of the compile() function.

Loss functions can be specified either using the name of a built in loss function (e.g. 'loss = binary_crossentropy'), a reference to a built in loss function (e.g. 'loss = loss_binary_crossentropy()') or by passing an artitrary function that returns a scalar for each data-point and takes the following two arguments:

  • y_true True labels (Tensor)

  • y_pred Predictions (Tensor of the same shape as y_true)

The actual optimized objective is the mean of the output array across all datapoints.

Categorical Crossentropy

When using the categorical_crossentropy loss, your targets should be in categorical format (e.g. if you have 10 classes, the target for each sample should be a 10-dimensional vector that is all-zeros expect for a 1 at the index corresponding to the class of the sample). In order to convert integer targets into categorical targets, you can use the Keras utility function to_categorical(): categorical_labels <- to_categorical(int_labels, num_classes = NULL)

See also

compile()