This callback is constructed with anonymous functions that will be called at the appropriate time. Note that the callbacks expects positional arguments, as:

• on_epoch_begin and on_epoch_end expect two positional arguments: epoch, logs

• on_batch_*, on_train_batch_*, on_predict_batch_* and on_test_batch_*, expect two positional arguments: batch, logs

• on_train_*, on_test_* and on_predict_* expect one positional argument: logs

callback_lambda(
on_epoch_begin = NULL,
on_epoch_end = NULL,
on_batch_begin = NULL,
on_batch_end = NULL,
on_train_batch_begin = NULL,
on_train_batch_end = NULL,
on_train_begin = NULL,
on_train_end = NULL,
on_predict_batch_begin = NULL,
on_predict_batch_end = NULL,
on_predict_begin = NULL,
on_predict_end = NULL,
on_test_batch_begin = NULL,
on_test_batch_end = NULL,
on_test_begin = NULL,
on_test_end = NULL
)

## Arguments

on_epoch_begin called at the beginning of every epoch. called at the end of every epoch. called at the beginning of every training batch. called at the end of every training batch. called at the beginning of every batch. called at the end of every batch. called at the beginning of model training. called at the end of model training. called at the beginning of a batch in predict methods. called at the end of a batch in predict methods. called at the beginning of prediction. called at the end of prediction. called at the beginning of a batch in evaluate methods. Also called at the beginning of a validation batch in the fit methods, if validation data is provided. called at the end of a batch in evaluate methods. Also called at the end of a validation batch in the fit methods, if validation data is provided. called at the beginning of evaluation or validation. called at the end of evaluation or validation.

Other callbacks: callback_csv_logger(), callback_early_stopping(), callback_learning_rate_scheduler(), callback_model_checkpoint(), callback_progbar_logger(), callback_reduce_lr_on_plateau(), callback_remote_monitor(), callback_tensorboard(), callback_terminate_on_naan()