metric_precision {keras3} | R Documentation |
Computes the precision of the predictions with respect to the labels.
Description
The metric creates two local variables, true_positives
and
false_positives
that are used to compute the precision. This value is
ultimately returned as precision
, an idempotent operation that simply
divides true_positives
by the sum of true_positives
and
false_positives
.
If sample_weight
is NULL
, weights default to 1.
Use sample_weight
of 0 to mask values.
If top_k
is set, we'll calculate precision as how often on average a class
among the top-k classes with the highest predicted values of a batch entry
is correct and can be found in the label for that entry.
If class_id
is specified, we calculate precision by considering only the
entries in the batch for which class_id
is above the threshold and/or in
the top-k highest predictions, and computing the fraction of them for which
class_id
is indeed a correct label.
Usage
metric_precision(
...,
thresholds = NULL,
top_k = NULL,
class_id = NULL,
name = NULL,
dtype = NULL
)
Arguments
... |
For forward/backward compatability. |
thresholds |
(Optional) A float value, or a Python list of float
threshold values in |
top_k |
(Optional) Unset by default. An int value specifying the top-k predictions to consider when calculating precision. |
class_id |
(Optional) Integer class ID for which we want binary metrics.
This must be in the half-open interval |
name |
(Optional) string name of the metric instance. |
dtype |
(Optional) data type of the metric result. |
Value
a Metric
instance is returned. The Metric
instance can be passed
directly to compile(metrics = )
, or used as a standalone object. See
?Metric
for example usage.
Usage
Standalone usage:
m <- metric_precision() m$update_state(c(0, 1, 1, 1), c(1, 0, 1, 1)) m$result() |> as.double() |> signif()
## [1] 0.666667
m$reset_state() m$update_state(c(0, 1, 1, 1), c(1, 0, 1, 1), sample_weight = c(0, 0, 1, 0)) m$result() |> as.double() |> signif()
## [1] 1
# With top_k=2, it will calculate precision over y_true[1:2] # and y_pred[1:2] m <- metric_precision(top_k = 2) m$update_state(c(0, 0, 1, 1), c(1, 1, 1, 1)) m$result()
## tf.Tensor(0.0, shape=(), dtype=float32)
# With top_k=4, it will calculate precision over y_true[1:4] # and y_pred[1:4] m <- metric_precision(top_k = 4) m$update_state(c(0, 0, 1, 1), c(1, 1, 1, 1)) m$result()
## tf.Tensor(0.5, shape=(), dtype=float32)
Usage with compile()
API:
model |> compile( optimizer = 'sgd', loss = 'binary_crossentropy', metrics = list(metric_precision()) )
Usage with a loss with from_logits=TRUE
:
model |> compile( optimizer = 'adam', loss = loss_binary_crossentropy(from_logits = TRUE), metrics = list(metric_precision(thresholds = 0)) )
See Also
Other confusion metrics:
metric_auc()
metric_false_negatives()
metric_false_positives()
metric_precision_at_recall()
metric_recall()
metric_recall_at_precision()
metric_sensitivity_at_specificity()
metric_specificity_at_sensitivity()
metric_true_negatives()
metric_true_positives()
Other metrics:
Metric()
custom_metric()
metric_auc()
metric_binary_accuracy()
metric_binary_crossentropy()
metric_binary_focal_crossentropy()
metric_binary_iou()
metric_categorical_accuracy()
metric_categorical_crossentropy()
metric_categorical_focal_crossentropy()
metric_categorical_hinge()
metric_cosine_similarity()
metric_f1_score()
metric_false_negatives()
metric_false_positives()
metric_fbeta_score()
metric_hinge()
metric_huber()
metric_iou()
metric_kl_divergence()
metric_log_cosh()
metric_log_cosh_error()
metric_mean()
metric_mean_absolute_error()
metric_mean_absolute_percentage_error()
metric_mean_iou()
metric_mean_squared_error()
metric_mean_squared_logarithmic_error()
metric_mean_wrapper()
metric_one_hot_iou()
metric_one_hot_mean_iou()
metric_poisson()
metric_precision_at_recall()
metric_r2_score()
metric_recall()
metric_recall_at_precision()
metric_root_mean_squared_error()
metric_sensitivity_at_specificity()
metric_sparse_categorical_accuracy()
metric_sparse_categorical_crossentropy()
metric_sparse_top_k_categorical_accuracy()
metric_specificity_at_sensitivity()
metric_squared_hinge()
metric_sum()
metric_top_k_categorical_accuracy()
metric_true_negatives()
metric_true_positives()