Package ai.djl.training.evaluator

Class AbstractAccuracy

java.lang.Object

ai.djl.training.evaluator.Evaluator

ai.djl.training.evaluator.AbstractAccuracy

Direct Known Subclasses:

Accuracy, BinaryAccuracy, SingleShotDetectionAccuracy, TopKAccuracy

public abstract class AbstractAccuracy
extends Evaluator

Accuracy is an Evaluator that computes the accuracy score.

The accuracy score is defined as \(accuracy(y, \hat{y}) = \frac{1}{n}\sum_{i=0}^{n-1}1(\hat{y_i} == y_i)\)

Field Summary

Fields

Modifier and Type	Field	Description
protected int	axis
protected java.util.Map<java.lang.String,java.lang.Long>	correctInstances

Fields inherited from class ai.djl.training.evaluator.Evaluator

totalInstances

Constructor Summary

Constructors

Constructor	Description
AbstractAccuracy(java.lang.String name)	Creates an accuracy evaluator that computes accuracy across axis 1.
AbstractAccuracy(java.lang.String name, int axis)	Creates an accuracy evaluator.

Method Summary

Modifier and Type	Method	Description
protected abstract ai.djl.util.Pair<java.lang.Long,NDArray>	accuracyHelper(NDList labels, NDList predictions)	A helper for classes extending AbstractAccuracy.
void	addAccumulator(java.lang.String key)	Adds an accumulator for the results of the evaluation with the given key.
NDArray	evaluate(NDList labels, NDList predictions)	Calculates the evaluation between the labels and the predictions.
float	getAccumulator(java.lang.String key)	Returns the accumulated evaluator value.
void	resetAccumulator(java.lang.String key)	Resets the evaluator value with the given key.
void	updateAccumulator(java.lang.String key, NDList labels, NDList predictions)	Updates the evaluator with the given key based on a NDList of labels and predictions.

Methods inherited from class ai.djl.training.evaluator.Evaluator

checkLabelShapes, checkLabelShapes, getName

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

correctInstances

protected java.util.Map<java.lang.String,java.lang.Long> correctInstances

axis

protected int axis

Constructor Detail

AbstractAccuracy

public AbstractAccuracy(java.lang.String name)

Creates an accuracy evaluator that computes accuracy across axis 1.

Parameters:

name - the name of the evaluator, default is "Accuracy"

AbstractAccuracy

public AbstractAccuracy(java.lang.String name,
                        int axis)

Creates an accuracy evaluator.

Parameters:

name - the name of the evaluator, default is "Accuracy"

axis - the axis that represent classes in prediction, default 1

Method Detail

accuracyHelper

protected abstract ai.djl.util.Pair<java.lang.Long,NDArray> accuracyHelper(NDList labels,
                                                                                 NDList predictions)

A helper for classes extending AbstractAccuracy.

Parameters:

labels - the labels to get accuracy for

predictions - the predictions to get accuracy for

Returns:

a pair(number of total values, ndarray int of correct values)

evaluate

public NDArray evaluate(NDList labels,
                        NDList predictions)

Calculates the evaluation between the labels and the predictions.

Specified by:

evaluate in class Evaluator

Parameters:

labels - the correct values

predictions - the predicted values

Returns:

the evaluation result

addAccumulator

public void addAccumulator(java.lang.String key)

Adds an accumulator for the results of the evaluation with the given key.

Specified by:

addAccumulator in class Evaluator

Parameters:

key - the key for the new accumulator

updateAccumulator

public void updateAccumulator(java.lang.String key,
                              NDList labels,
                              NDList predictions)

Updates the evaluator with the given key based on a NDList of labels and predictions.

This is a synchronized operation. You should only call it at the end of a batch or epoch.

Specified by:

updateAccumulator in class Evaluator

Parameters:

key - the key of the accumulator to update

labels - a NDList of labels

predictions - a NDList of predictions

resetAccumulator

public void resetAccumulator(java.lang.String key)

Resets the evaluator value with the given key.

Specified by:

resetAccumulator in class Evaluator

Parameters:

key - the key of the accumulator to reset

getAccumulator

public float getAccumulator(java.lang.String key)

Returns the accumulated evaluator value.

Specified by:

getAccumulator in class Evaluator

Parameters:

key - the key of the accumulator to get

Returns:

the accumulated value