This functions returns the loss value and metrics values for the model in
test mode.
Computation is done in batches (see the batch_size
arg.)
# S3 method for keras.src.models.model.Model
evaluate(
object,
x = NULL,
y = NULL,
...,
batch_size = NULL,
verbose = getOption("keras.verbose", default = "auto"),
sample_weight = NULL,
steps = NULL,
callbacks = NULL
)
Scalar test loss (if the model has a single output and no metrics)
or list of scalars (if the model has multiple outputs
and/or metrics). The attribute model$metrics_names
will give you
the display labels for the scalar outputs.
Keras model object
Input data. It could be:
An R array (or array-like), or a list of arrays (in case the model has multiple inputs).
A tensor, or a list of tensors (in case the model has multiple inputs).
A named list mapping input names to the corresponding array/tensors, if the model has named inputs.
A tf.data.Dataset
. Should return a tuple
of either (inputs, targets)
or
(inputs, targets, sample_weights)
.
A generator returning
(inputs, targets)
or (inputs, targets, sample_weights)
.
Target data. Like the input data x
, it could be either R
array(s) or backend-native tensor(s).
If x
is a tf.data.Dataset
or generator function,
y
should not be specified
(since targets will be obtained from the iterator/dataset).
For forward/backward compatability.
Integer or NULL
. Number of samples per batch of
computation. If unspecified, batch_size
will default to 32
. Do
not specify the batch_size
if your data is in the form of a
a tf dataset or generator
(since they generate batches).
"auto"
, 0
, 1
, or 2
. Verbosity mode.
0
= silent, 1
= progress bar, 2
= single line.
"auto"
becomes 1
for most cases,
2
if in a knitr render or running on a distributed training server.
Note that the progress bar is not
particularly useful when logged to a file, so verbose=2
is
recommended when not running interactively
(e.g. in a production environment). Defaults to "auto"
.
Optional array of weights for the test samples,
used for weighting the loss function. You can either pass a flat
(1D) R array with the same length as the input samples
(1:1 mapping between weights and samples), or 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. This argument is not supported when
x
is a tfdataset, instead pass sample weights as the third
element of x
.
Integer or NULL
. Total number of steps (batches of samples)
before declaring the evaluation round finished. Ignored with the
default value of NULL
. If x
is a tf.data.Dataset
and
steps
is NULL
, evaluation will run until the dataset
is exhausted.
List of Callback
instances.
List of callbacks to apply during evaluation.
Other model training:
compile.keras.src.models.model.Model()
predict.keras.src.models.model.Model()
predict_on_batch()
test_on_batch()
train_on_batch()