[FIXED] Plotting already calculated Confusion Matrix using Python

Issue

How can I plot in Python a Confusion Matrix similar do the one shown here for already given values of the Confusion Matrix?

In the code they use the method sklearn.metrics.plot_confusion_matrix which computes the Confusion Matrix based on the ground truth and the predictions.

But in my case, I already have calculated my Confusion Matrix. So for example, my Confusion Matrix is (values in percentages):

[[0.612, 0.388]
 [0.228, 0.772]]

Solution

If you check the source for sklearn.metrics.plot_confusion_matrix, you can see how the data is processed to create the plot. Then you can reuse the constructor ConfusionMatrixDisplay and plot your own confusion matrix.

import matplotlib.pyplot as plt
from sklearn.metrics import ConfusionMatrixDisplay

cm = [0.612, 0.388, 0.228, 0.772] # your confusion matrix
ls = [0, 1] # your y labels
disp = ConfusionMatrixDisplay(confusion_matrix=cm, display_labels=ls)
disp.plot(include_values=include_values, cmap=cmap, ax=ax, xticks_rotation=xticks_rotation)
plt.show()

Answered By - ilke444