keras/keras_core/metrics/confusion_metrics.py
Francois Chollet ae105069a3 Fix typos
2023-05-02 15:23:08 -07:00

547 lines
21 KiB
Python

from keras_core import backend
from keras_core import initializers
from keras_core import operations as ops
from keras_core.api_export import keras_core_export
from keras_core.metrics import metrics_utils
from keras_core.metrics.metric import Metric
from keras_core.utils.python_utils import to_list
class _ConfusionMatrixConditionCount(Metric):
"""Calculates the number of the given confusion matrix condition.
Args:
confusion_matrix_cond: One of `metrics_utils.ConfusionMatrix`
conditions.
thresholds: (Optional) Defaults to 0.5. A float value or a python list /
tuple of float threshold values in `[0, 1]`. A threshold is compared
with prediction values to determine the truth value of predictions
(i.e., above the threshold is `True`, below is `False`). One metric
value is generated for each threshold value.
name: (Optional) string name of the metric instance.
dtype: (Optional) data type of the metric result.
"""
def __init__(
self, confusion_matrix_cond, thresholds=None, name=None, dtype=None
):
super().__init__(name=name, dtype=dtype)
self._confusion_matrix_cond = confusion_matrix_cond
self.init_thresholds = thresholds
self.thresholds = metrics_utils.parse_init_thresholds(
thresholds, default_threshold=0.5
)
self._thresholds_distributed_evenly = (
metrics_utils.is_evenly_distributed_thresholds(self.thresholds)
)
self.accumulator = self.add_variable(
shape=(len(self.thresholds),),
initializer=initializers.Zeros(),
name="accumulator",
)
def update_state(self, y_true, y_pred, sample_weight=None):
"""Accumulates the metric statistics.
Args:
y_true: The ground truth values.
y_pred: The predicted values.
sample_weight: Optional weighting of each example. Defaults to 1.
Can be a tensor whose rank is either 0, or the same rank as
`y_true`, and must be broadcastable to `y_true`.
"""
return metrics_utils.update_confusion_matrix_variables(
{self._confusion_matrix_cond: self.accumulator},
y_true,
y_pred,
thresholds=self.thresholds,
thresholds_distributed_evenly=self._thresholds_distributed_evenly,
sample_weight=sample_weight,
)
def result(self):
if len(self.thresholds) == 1:
result = self.accumulator[0]
else:
result = self.accumulator
return backend.convert_to_tensor(result)
def get_config(self):
config = {"thresholds": self.init_thresholds}
base_config = super().get_config()
return dict(list(base_config.items()) + list(config.items()))
@keras_core_export("keras_core.metrics.FalsePositives")
class FalsePositives(_ConfusionMatrixConditionCount):
"""Calculates the number of false positives.
If `sample_weight` is given, calculates the sum of the weights of
false positives. This metric creates one local variable, `accumulator`
that is used to keep track of the number of false positives.
If `sample_weight` is `None`, weights default to 1.
Use `sample_weight` of 0 to mask values.
Args:
thresholds: (Optional) Defaults to 0.5. A float value, or a Python
list/tuple of float threshold values in `[0, 1]`. A threshold is
compared with prediction values to determine the truth value of
predictions (i.e., above the threshold is `True`, below is `False`).
If used with a loss function that sets `from_logits=True` (i.e. no
sigmoid applied to predictions), `thresholds` should be set to 0.
One metric value is generated for each threshold value.
name: (Optional) string name of the metric instance.
dtype: (Optional) data type of the metric result.
Standalone usage:
>>> m = keras_core.metrics.FalsePositives()
>>> m.update_state([0, 1, 0, 0], [0, 0, 1, 1])
>>> m.result()
2.0
>>> m.reset_state()
>>> m.update_state([0, 1, 0, 0], [0, 0, 1, 1], sample_weight=[0, 0, 1, 0])
>>> m.result()
1.0
"""
def __init__(self, thresholds=None, name=None, dtype=None):
super().__init__(
confusion_matrix_cond=metrics_utils.ConfusionMatrix.FALSE_POSITIVES,
thresholds=thresholds,
name=name,
dtype=dtype,
)
@keras_core_export("keras_core.metrics.FalseNegatives")
class FalseNegatives(_ConfusionMatrixConditionCount):
"""Calculates the number of false negatives.
If `sample_weight` is given, calculates the sum of the weights of
false negatives. This metric creates one local variable, `accumulator`
that is used to keep track of the number of false negatives.
If `sample_weight` is `None`, weights default to 1.
Use `sample_weight` of 0 to mask values.
Args:
thresholds: (Optional) Defaults to 0.5. A float value, or a Python
list/tuple of float threshold values in `[0, 1]`. A threshold is
compared with prediction values to determine the truth value of
predictions (i.e., above the threshold is `True`, below is `False`).
If used with a loss function that sets `from_logits=True` (i.e. no
sigmoid applied to predictions), `thresholds` should be set to 0.
One metric value is generated for each threshold value.
name: (Optional) string name of the metric instance.
dtype: (Optional) data type of the metric result.
Standalone usage:
>>> m = keras_core.metrics.FalseNegatives()
>>> m.update_state([0, 1, 1, 1], [0, 1, 0, 0])
>>> m.result()
2.0
>>> m.reset_state()
>>> m.update_state([0, 1, 1, 1], [0, 1, 0, 0], sample_weight=[0, 0, 1, 0])
>>> m.result()
1.0
"""
def __init__(self, thresholds=None, name=None, dtype=None):
super().__init__(
confusion_matrix_cond=metrics_utils.ConfusionMatrix.FALSE_NEGATIVES,
thresholds=thresholds,
name=name,
dtype=dtype,
)
@keras_core_export("keras_core.metrics.TrueNegatives")
class TrueNegatives(_ConfusionMatrixConditionCount):
"""Calculates the number of true negatives.
If `sample_weight` is given, calculates the sum of the weights of
true negatives. This metric creates one local variable, `accumulator`
that is used to keep track of the number of true negatives.
If `sample_weight` is `None`, weights default to 1.
Use `sample_weight` of 0 to mask values.
Args:
thresholds: (Optional) Defaults to 0.5. A float value, or a Python
list/tuple of float threshold values in `[0, 1]`. A threshold is
compared with prediction values to determine the truth value of
predictions (i.e., above the threshold is `True`, below is `False`).
If used with a loss function that sets `from_logits=True` (i.e. no
sigmoid applied to predictions), `thresholds` should be set to 0.
One metric value is generated for each threshold value.
name: (Optional) string name of the metric instance.
dtype: (Optional) data type of the metric result.
Standalone usage:
>>> m = keras_core.metrics.TrueNegatives()
>>> m.update_state([0, 1, 0, 0], [1, 1, 0, 0])
>>> m.result()
2.0
>>> m.reset_state()
>>> m.update_state([0, 1, 0, 0], [1, 1, 0, 0], sample_weight=[0, 0, 1, 0])
>>> m.result()
1.0
"""
def __init__(self, thresholds=None, name=None, dtype=None):
super().__init__(
confusion_matrix_cond=metrics_utils.ConfusionMatrix.TRUE_NEGATIVES,
thresholds=thresholds,
name=name,
dtype=dtype,
)
@keras_core_export("keras_core.metrics.TruePositives")
class TruePositives(_ConfusionMatrixConditionCount):
"""Calculates the number of true positives.
If `sample_weight` is given, calculates the sum of the weights of
true positives. This metric creates one local variable, `true_positives`
that is used to keep track of the number of true positives.
If `sample_weight` is `None`, weights default to 1.
Use `sample_weight` of 0 to mask values.
Args:
thresholds: (Optional) Defaults to 0.5. A float value, or a Python
list/tuple of float threshold values in `[0, 1]`. A threshold is
compared with prediction values to determine the truth value of
predictions (i.e., above the threshold is `True`, below is `False`).
If used with a loss function that sets `from_logits=True` (i.e. no
sigmoid applied to predictions), `thresholds` should be set to 0.
One metric value is generated for each threshold value.
name: (Optional) string name of the metric instance.
dtype: (Optional) data type of the metric result.
Standalone usage:
>>> m = keras_core.metrics.TruePositives()
>>> m.update_state([0, 1, 1, 1], [1, 0, 1, 1])
>>> m.result()
2.0
>>> m.reset_state()
>>> m.update_state([0, 1, 1, 1], [1, 0, 1, 1], sample_weight=[0, 0, 1, 0])
>>> m.result()
1.0
"""
def __init__(self, thresholds=None, name=None, dtype=None):
super().__init__(
confusion_matrix_cond=metrics_utils.ConfusionMatrix.TRUE_POSITIVES,
thresholds=thresholds,
name=name,
dtype=dtype,
)
@keras_core_export("keras_core.metrics.Precision")
class Precision(Metric):
"""Computes the precision of the predictions with respect to the labels.
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 `None`, 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.
Args:
thresholds: (Optional) A float value, or a Python list/tuple of float
threshold values in `[0, 1]`. A threshold is compared with
prediction values to determine the truth value of predictions (i.e.,
above the threshold is `True`, below is `False`). If used with a
loss function that sets `from_logits=True` (i.e. no sigmoid applied
to predictions), `thresholds` should be set to 0. One metric value
is generated for each threshold value. If neither `thresholds` nor
`top_k` are set, the default is to calculate precision with
`thresholds=0.5`.
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 `[0, num_classes)`, where
`num_classes` is the last dimension of predictions.
name: (Optional) string name of the metric instance.
dtype: (Optional) data type of the metric result.
Standalone usage:
>>> m = keras_core.metrics.Precision()
>>> m.update_state([0, 1, 1, 1], [1, 0, 1, 1])
>>> m.result()
0.6666667
>>> m.reset_state()
>>> m.update_state([0, 1, 1, 1], [1, 0, 1, 1], sample_weight=[0, 0, 1, 0])
>>> m.result()
1.0
>>> # With top_k=2, it will calculate precision over y_true[:2]
>>> # and y_pred[:2]
>>> m = keras_core.metrics.Precision(top_k=2)
>>> m.update_state([0, 0, 1, 1], [1, 1, 1, 1])
>>> m.result()
0.0
>>> # With top_k=4, it will calculate precision over y_true[:4]
>>> # and y_pred[:4]
>>> m = keras_core.metrics.Precision(top_k=4)
>>> m.update_state([0, 0, 1, 1], [1, 1, 1, 1])
>>> m.result()
0.5
Usage with `compile()` API:
```python
model.compile(optimizer='sgd',
loss='mse',
metrics=[keras_core.metrics.Precision()])
```
Usage with a loss with `from_logits=True`:
```python
model.compile(optimizer='adam',
loss=keras_core.losses.BinaryCrossentropy(from_logits=True),
metrics=[keras_core.metrics.Precision(thresholds=0)])
```
"""
def __init__(
self, thresholds=None, top_k=None, class_id=None, name=None, dtype=None
):
super().__init__(name=name, dtype=dtype)
self.init_thresholds = thresholds
self.top_k = top_k
self.class_id = class_id
default_threshold = 0.5 if top_k is None else metrics_utils.NEG_INF
self.thresholds = metrics_utils.parse_init_thresholds(
thresholds, default_threshold=default_threshold
)
self._thresholds_distributed_evenly = (
metrics_utils.is_evenly_distributed_thresholds(self.thresholds)
)
self.true_positives = self.add_variable(
shape=(len(self.thresholds),),
initializer=initializers.Zeros(),
name="true_positives",
)
self.false_positives = self.add_variable(
shape=(len(self.thresholds),),
initializer=initializers.Zeros(),
name="false_positives",
)
def update_state(self, y_true, y_pred, sample_weight=None):
"""Accumulates true positive and false positive statistics.
Args:
y_true: The ground truth values, with the same dimensions as
`y_pred`. Will be cast to `bool`.
y_pred: The predicted values. Each element must be in the range
`[0, 1]`.
sample_weight: Optional weighting of each example. Defaults to 1.
Can be a `Tensor` whose rank is either 0, or the same rank as
`y_true`, and must be broadcastable to `y_true`.
"""
metrics_utils.update_confusion_matrix_variables(
{
metrics_utils.ConfusionMatrix.TRUE_POSITIVES: self.true_positives, # noqa: E501
metrics_utils.ConfusionMatrix.FALSE_POSITIVES: self.false_positives, # noqa: E501
},
y_true,
y_pred,
thresholds=self.thresholds,
thresholds_distributed_evenly=self._thresholds_distributed_evenly,
top_k=self.top_k,
class_id=self.class_id,
sample_weight=sample_weight,
)
def result(self):
result = ops.divide(
self.true_positives,
self.true_positives + self.false_positives + backend.epsilon(),
)
return result[0] if len(self.thresholds) == 1 else result
def reset_state(self):
num_thresholds = len(to_list(self.thresholds))
self.true_positives.assign(ops.zeros((num_thresholds,)))
self.false_positives.assign(ops.zeros((num_thresholds,)))
def get_config(self):
config = {
"thresholds": self.init_thresholds,
"top_k": self.top_k,
"class_id": self.class_id,
}
base_config = super().get_config()
return dict(list(base_config.items()) + list(config.items()))
@keras_core_export("keras_core.metrics.Recall")
class Recall(Metric):
"""Computes the recall of the predictions with respect to the labels.
This metric creates two local variables, `true_positives` and
`false_negatives`, that are used to compute the recall. This value is
ultimately returned as `recall`, an idempotent operation that simply divides
`true_positives` by the sum of `true_positives` and `false_negatives`.
If `sample_weight` is `None`, weights default to 1.
Use `sample_weight` of 0 to mask values.
If `top_k` is set, recall will be computed as how often on average a class
among the labels of a batch entry is in the top-k predictions.
If `class_id` is specified, we calculate recall by considering only the
entries in the batch for which `class_id` is in the label, and computing the
fraction of them for which `class_id` is above the threshold and/or in the
top-k predictions.
Args:
thresholds: (Optional) A float value, or a Python list/tuple of float
threshold values in `[0, 1]`. A threshold is compared with
prediction values to determine the truth value of predictions (i.e.,
above the threshold is `True`, below is `False`). If used with a
loss function that sets `from_logits=True` (i.e. no sigmoid
applied to predictions), `thresholds` should be set to 0.
One metric value is generated for each threshold value.
If neither `thresholds` nor `top_k` are set,
the default is to calculate recall with `thresholds=0.5`.
top_k: (Optional) Unset by default. An int value specifying the top-k
predictions to consider when calculating recall.
class_id: (Optional) Integer class ID for which we want binary metrics.
This must be in the half-open interval `[0, num_classes)`, where
`num_classes` is the last dimension of predictions.
name: (Optional) string name of the metric instance.
dtype: (Optional) data type of the metric result.
Standalone usage:
>>> m = keras_core.metrics.Recall()
>>> m.update_state([0, 1, 1, 1], [1, 0, 1, 1])
>>> m.result()
0.6666667
>>> m.reset_state()
>>> m.update_state([0, 1, 1, 1], [1, 0, 1, 1], sample_weight=[0, 0, 1, 0])
>>> m.result()
1.0
Usage with `compile()` API:
```python
model.compile(optimizer='sgd',
loss='mse',
metrics=[keras_core.metrics.Recall()])
```
Usage with a loss with `from_logits=True`:
```python
model.compile(optimizer='adam',
loss=keras_core.losses.BinaryCrossentropy(from_logits=True),
metrics=[keras_core.metrics.Recall(thresholds=0)])
```
"""
def __init__(
self, thresholds=None, top_k=None, class_id=None, name=None, dtype=None
):
super().__init__(name=name, dtype=dtype)
self.init_thresholds = thresholds
self.top_k = top_k
self.class_id = class_id
default_threshold = 0.5 if top_k is None else metrics_utils.NEG_INF
self.thresholds = metrics_utils.parse_init_thresholds(
thresholds, default_threshold=default_threshold
)
self._thresholds_distributed_evenly = (
metrics_utils.is_evenly_distributed_thresholds(self.thresholds)
)
self.true_positives = self.add_variable(
shape=(len(self.thresholds),),
initializer=initializers.Zeros(),
name="true_positives",
)
self.false_negatives = self.add_variable(
shape=(len(self.thresholds),),
initializer=initializers.Zeros(),
name="false_negatives",
)
def update_state(self, y_true, y_pred, sample_weight=None):
"""Accumulates true positive and false negative statistics.
Args:
y_true: The ground truth values, with the same dimensions as
`y_pred`. Will be cast to `bool`.
y_pred: The predicted values. Each element must be in the range
`[0, 1]`.
sample_weight: Optional weighting of each example. Defaults to 1.
Can be a `Tensor` whose rank is either 0, or the same rank as
`y_true`, and must be broadcastable to `y_true`.
"""
metrics_utils.update_confusion_matrix_variables(
{
metrics_utils.ConfusionMatrix.TRUE_POSITIVES: self.true_positives, # noqa: E501
metrics_utils.ConfusionMatrix.FALSE_NEGATIVES: self.false_negatives, # noqa: E501
},
y_true,
y_pred,
thresholds=self.thresholds,
thresholds_distributed_evenly=self._thresholds_distributed_evenly,
top_k=self.top_k,
class_id=self.class_id,
sample_weight=sample_weight,
)
def result(self):
result = ops.divide(
self.true_positives,
self.true_positives + self.false_negatives + backend.epsilon(),
)
return result[0] if len(self.thresholds) == 1 else result
def reset_state(self):
num_thresholds = len(to_list(self.thresholds))
self.true_positives.assign(ops.zeros((num_thresholds,)))
self.false_negatives.assign(ops.zeros((num_thresholds,)))
def get_config(self):
config = {
"thresholds": self.init_thresholds,
"top_k": self.top_k,
"class_id": self.class_id,
}
base_config = super().get_config()
return dict(list(base_config.items()) + list(config.items()))