Trains the model for a fixed number of epochs (iterations on a dataset).
# S3 method for keras.engine.training.Model
fit(
object,
x = NULL,
y = NULL,
batch_size = NULL,
epochs = 10,
verbose = getOption("keras.fit_verbose", default = "auto"),
callbacks = NULL,
view_metrics = getOption("keras.view_metrics", default = "auto"),
validation_split = 0,
validation_data = NULL,
shuffle = TRUE,
class_weight = NULL,
sample_weight = NULL,
initial_epoch = 0,
steps_per_epoch = NULL,
validation_steps = NULL,
...
)
A history
object that contains all information collected during
training.
Model to train.
Vector, matrix, or array of training data (or list if the model has
multiple inputs). If all inputs in the model are named, you can also pass a
list mapping input names to data. x
can be NULL
(default) if feeding
from framework-native tensors (e.g. TensorFlow data tensors). You can also
pass a tfdataset
or a generator returning a list with (inputs, targets)
or (inputs, targets, sample_weights)
.
Vector, matrix, or array of target (label) data (or list if the
model has multiple outputs). If all outputs in the model are named, you can
also pass a list mapping output names to data. y
can be NULL
(default)
if feeding from framework-native tensors (e.g. TensorFlow data tensors).
Integer or NULL
. Number of samples per gradient update.
If unspecified, batch_size
will default to 32.
Number of epochs to train the model. Note that in conjunction
with initial_epoch
, epochs
is to be understood as "final epoch". The
model is not trained for a number of iterations given by epochs
, but
merely until the epoch of index epochs
is reached.
Verbosity mode (0 = silent, 1 = progress bar, 2 = one line per epoch). Defaults to 1 in most contexts, 2 if in knitr render or running on a distributed training server.
List of callbacks to be called during training.
View realtime plot of training metrics (by epoch). The
default ("auto"
) will display the plot when running within RStudio,
metrics
were specified during model compile()
, epochs > 1
and
verbose > 0
. Use the global keras.view_metrics
option to establish a
different default.
Float between 0 and 1. Fraction of the training data
to be used as validation data. The model will set apart this fraction of
the training data, will not train on it, and will evaluate the loss and any
model metrics on this data at the end of each epoch. The validation data is
selected from the last samples in the x
and y
data provided, before
shuffling.
Data on which to evaluate the loss and any model
metrics at the end of each epoch. The model will not be trained on this
data. This could be a list (x_val, y_val) or a list (x_val, y_val,
val_sample_weights). validation_data
will override validation_split
.
shuffle: Logical (whether to shuffle the training data before
each epoch) or string (for "batch"). "batch" is a special option for
dealing with the limitations of HDF5 data; it shuffles in batch-sized
chunks. Has no effect when steps_per_epoch
is not NULL
.
Optional named list mapping indices (integers) to a weight (float) value, used for weighting the loss function (during training only). This can be useful to tell the model to "pay more attention" to samples from an under-represented class.
Optional array of the same length as x, containing
weights to apply to the model's loss for each sample. In the case of
temporal data, you can pass a 2D array with shape (samples,
sequence_length), to apply a different weight to every timestep of every
sample. In this case you should make sure to specify
sample_weight_mode="temporal"
in compile()
.
Integer, Epoch at which to start training (useful for resuming a previous training run).
Total number of steps (batches of samples) before
declaring one epoch finished and starting the next epoch. When training
with input tensors such as TensorFlow data tensors, the default NULL
is
equal to the number of samples in your dataset divided by the batch size,
or 1 if that cannot be determined.
Only relevant if steps_per_epoch
is specified.
Total number of steps (batches of samples) to validate before stopping.
Unused
Other model functions:
compile.keras.engine.training.Model()
,
evaluate.keras.engine.training.Model()
,
evaluate_generator()
,
fit_generator()
,
get_config()
,
get_layer()
,
keras_model_sequential()
,
keras_model()
,
multi_gpu_model()
,
pop_layer()
,
predict.keras.engine.training.Model()
,
predict_generator()
,
predict_on_batch()
,
predict_proba()
,
summary.keras.engine.training.Model()
,
train_on_batch()