ee.ConfusionMatrix.kappa
Computes the Kappa statistic for the confusion matrix.
Usage | Returns |
---|
ConfusionMatrix.kappa() | Float |
Argument | Type | Details |
---|
this: confusionMatrix | ConfusionMatrix | |
Examples
// Construct a confusion matrix from an array (rows are actual values,
// columns are predicted values). We construct a confusion matrix here for
// brevity and clear visualization, in most applications the confusion matrix
// will be generated from ee.Classifier.confusionMatrix.
var array = ee.Array([[32, 0, 0, 0, 1, 0],
[ 0, 5, 0, 0, 1, 0],
[ 0, 0, 1, 3, 0, 0],
[ 0, 1, 4, 26, 8, 0],
[ 0, 0, 0, 7, 15, 0],
[ 0, 0, 0, 1, 0, 5]]);
var confusionMatrix = ee.ConfusionMatrix(array);
print("Constructed confusion matrix", confusionMatrix);
// Calculate overall accuracy.
print("Overall accuracy", confusionMatrix.accuracy());
// Calculate consumer's accuracy, also known as user's accuracy or
// specificity and the complement of commission error (1 − commission error).
print("Consumer's accuracy", confusionMatrix.consumersAccuracy());
// Calculate producer's accuracy, also known as sensitivity and the
// compliment of omission error (1 − omission error).
print("Producer's accuracy", confusionMatrix.producersAccuracy());
// Calculate kappa statistic.
print('Kappa statistic', confusionMatrix.kappa());
Python setup
See the
Python Environment page for information on the Python API and using
geemap
for interactive development.
import ee
import geemap.core as geemap
from pprint import pprint
# Construct a confusion matrix from an array (rows are actual values,
# columns are predicted values). We construct a confusion matrix here for
# brevity and clear visualization, in most applications the confusion matrix
# will be generated from ee.Classifier.confusionMatrix.
array = ee.Array([[32, 0, 0, 0, 1, 0],
[ 0, 5, 0, 0, 1, 0],
[ 0, 0, 1, 3, 0, 0],
[ 0, 1, 4, 26, 8, 0],
[ 0, 0, 0, 7, 15, 0],
[ 0, 0, 0, 1, 0, 5]])
confusion_matrix = ee.ConfusionMatrix(array)
print("Constructed confusion matrix:")
pprint(confusion_matrix.getInfo())
# Calculate overall accuracy.
print("Overall accuracy:", confusion_matrix.accuracy().getInfo())
# Calculate consumer's accuracy, also known as user's accuracy or
# specificity and the complement of commission error (1 − commission error).
print("Consumer's accuracy:")
pprint(confusion_matrix.consumersAccuracy().getInfo())
# Calculate producer's accuracy, also known as sensitivity and the
# compliment of omission error (1 − omission error).
print("Producer's accuracy:")
pprint(confusion_matrix.producersAccuracy().getInfo())
# Calculate kappa statistic.
print("Kappa statistic:", confusion_matrix.kappa().getInfo())
Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License. For details, see the Google Developers Site Policies. Java is a registered trademark of Oracle and/or its affiliates.
Last updated 2023-10-06 UTC.
[null,null,["Last updated 2023-10-06 UTC."],[[["Computes the Kappa statistic, a measure of agreement between predicted and actual classifications, for a given confusion matrix."],["The `kappa()` function takes a `confusionMatrix` object as input and returns the Kappa statistic as a float."],["This function is part of the Earth Engine API and can be used to evaluate the performance of classification models."],["Usage examples are provided in JavaScript and Python for calculating the Kappa statistic from a confusion matrix."]]],["The `ConfusionMatrix.kappa()` method computes the Kappa statistic, returning a float value. This method operates on a confusion matrix, which is typically generated from a classifier. The provided examples demonstrate constructing a confusion matrix from an array, then utilizing `kappa()` to calculate the Kappa statistic. They also showcase related accuracy metrics like overall, consumer's, and producer's accuracy.\n"]]