ConfusionMatrixDisplay#

classsklearn.metrics.ConfusionMatrixDisplay(confusion_matrix, *, display_labels=None)[source] #

Confusion Matrix visualization.

It is recommended to use from_estimator or from_predictions to create a ConfusionMatrixDisplay. All parameters are stored as attributes.

For general information regarding scikit-learn visualization tools, see the Visualization Guide. For guidance on interpreting these plots, refer to the Model Evaluation Guide.

Parameters:

confusion_matrixndarray of shape (n_classes, n_classes): Confusion matrix.
display_labelsndarray of shape (n_classes,), default=None: Display labels for plot. If None, display labels are set from 0 to n_classes - 1.

Attributes:

im_matplotlib AxesImage: Image representing the confusion matrix.
text_ndarray of shape (n_classes, n_classes), dtype=matplotlib Text, or None: Array of matplotlib axes. None if include_values is false.
ax_matplotlib Axes: Axes with confusion matrix.
figure_matplotlib Figure: Figure containing the confusion matrix.

See also

confusion_matrix: Compute Confusion Matrix to evaluate the accuracy of a classification.
ConfusionMatrixDisplay.from_estimator: Plot the confusion matrix given an estimator, the data, and the label.
ConfusionMatrixDisplay.from_predictions: Plot the confusion matrix given the true and predicted labels.

Examples

>>> importmatplotlib.pyplotasplt
>>> fromsklearn.datasetsimport make_classification
>>> fromsklearn.metricsimport confusion_matrix, ConfusionMatrixDisplay
>>> fromsklearn.model_selectionimport train_test_split
>>> fromsklearn.svmimport SVC
>>> X, y = make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(X, y,
...  random_state=0)
>>> clf = SVC(random_state=0)
>>> clf.fit(X_train, y_train)
SVC(random_state=0)
>>> predictions = clf.predict(X_test)
>>> cm = confusion_matrix(y_test, predictions, labels=clf.classes_)
>>> disp = ConfusionMatrixDisplay(confusion_matrix=cm,
...  display_labels=clf.classes_)
>>> disp.plot()
<...>
>>> plt.show()

../../_images/sklearn-metrics-ConfusionMatrixDisplay-1.png

classmethodfrom_estimator(estimator, X, y, *, labels=None, sample_weight=None, normalize=None, display_labels=None, include_values=True, xticks_rotation='horizontal', values_format=None, cmap='viridis', ax=None, colorbar=True, im_kw=None, text_kw=None)[source] #

Plot Confusion Matrix given an estimator and some data.

For general information regarding scikit-learn visualization tools, see the Visualization Guide. For guidance on interpreting these plots, refer to the Model Evaluation Guide.

Added in version 1.0.

Parameters:

estimatorestimator instance

Fitted classifier or a fitted Pipeline in which the last estimator is a classifier.

X{array-like, sparse matrix} of shape (n_samples, n_features)

Input values.

yarray-like of shape (n_samples,)

Target values.

labelsarray-like of shape (n_classes,), default=None

List of labels to index the confusion matrix. This may be used to reorder or select a subset of labels. If None is given, those that appear at least once in y_true or y_pred are used in sorted order.

sample_weightarray-like of shape (n_samples,), default=None

Sample weights.

normalize{‘true’, ‘pred’, ‘all’}, default=None

Either to normalize the counts display in the matrix:

if 'true', the confusion matrix is normalized over the true conditions (e.g. rows);
if 'pred', the confusion matrix is normalized over the predicted conditions (e.g. columns);
if 'all', the confusion matrix is normalized by the total number of samples;
if None (default), the confusion matrix will not be normalized.

display_labelsarray-like of shape (n_classes,), default=None

Target names used for plotting. By default, labels will be used if it is defined, otherwise the unique labels of y_true and y_pred will be used.

include_valuesbool, default=True

Includes values in confusion matrix.

xticks_rotation{‘vertical’, ‘horizontal’} or float, default=’horizontal’

Rotation of xtick labels.

values_formatstr, default=None

Format specification for values in confusion matrix. If None, the format specification is ‘d’ or ‘.2g’ whichever is shorter.

cmapstr or matplotlib Colormap, default=’viridis’

Colormap recognized by matplotlib.

axmatplotlib Axes, default=None

Axes object to plot on. If None, a new figure and axes is created.

colorbarbool, default=True

Whether or not to add a colorbar to the plot.

im_kwdict, default=None

Dict with keywords passed to matplotlib.pyplot.imshow call.

text_kwdict, default=None

Dict with keywords passed to matplotlib.pyplot.text call.

Added in version 1.2.

Returns:

displayConfusionMatrixDisplay

See also

ConfusionMatrixDisplay.from_predictions: Plot the confusion matrix given the true and predicted labels.

Examples

>>> importmatplotlib.pyplotasplt
>>> fromsklearn.datasetsimport make_classification
>>> fromsklearn.metricsimport ConfusionMatrixDisplay
>>> fromsklearn.model_selectionimport train_test_split
>>> fromsklearn.svmimport SVC
>>> X, y = make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
...  X, y, random_state=0)
>>> clf = SVC(random_state=0)
>>> clf.fit(X_train, y_train)
SVC(random_state=0)
>>> ConfusionMatrixDisplay.from_estimator(
...  clf, X_test, y_test)
<...>
>>> plt.show()

../../_images/sklearn-metrics-ConfusionMatrixDisplay-2_00_00.png

For a detailed example of using a confusion matrix to evaluate a Support Vector Classifier, please see Confusion matrix

classmethodfrom_predictions(y_true, y_pred, *, labels=None, sample_weight=None, normalize=None, display_labels=None, include_values=True, xticks_rotation='horizontal', values_format=None, cmap='viridis', ax=None, colorbar=True, im_kw=None, text_kw=None)[source] #

Plot Confusion Matrix given true and predicted labels.

For general information regarding scikit-learn visualization tools, see the Visualization Guide. For guidance on interpreting these plots, refer to the Model Evaluation Guide.

Added in version 1.0.

Parameters:

y_truearray-like of shape (n_samples,)

True labels.

y_predarray-like of shape (n_samples,)

The predicted labels given by the method predict of an classifier.

labelsarray-like of shape (n_classes,), default=None

sample_weightarray-like of shape (n_samples,), default=None

Sample weights.

normalize{‘true’, ‘pred’, ‘all’}, default=None

Either to normalize the counts display in the matrix:

if 'true', the confusion matrix is normalized over the true conditions (e.g. rows);
if 'pred', the confusion matrix is normalized over the predicted conditions (e.g. columns);
if 'all', the confusion matrix is normalized by the total number of samples;
if None (default), the confusion matrix will not be normalized.

display_labelsarray-like of shape (n_classes,), default=None

Target names used for plotting. By default, labels will be used if it is defined, otherwise the unique labels of y_true and y_pred will be used.

include_valuesbool, default=True