Supports all values that can be represented as a string
callback_csv_logger(filename, separator = ",", append = FALSE)filename of the csv file, e.g. 'run/log.csv'.
string used to separate elements in the csv file.
TRUE: append if file exists (useful for continuing training).
FALSE: overwrite existing file,
Other callbacks: callback_early_stopping,
callback_lambda,
callback_learning_rate_scheduler,
callback_model_checkpoint,
callback_progbar_logger,
callback_reduce_lr_on_plateau,
callback_remote_monitor,
callback_tensorboard,
callback_terminate_on_naan