Confusion matrixes
A confusion matrix is a figure or a table that is used to describe the performance of a classifier. Each row in the matrix represents the instances in a predicted class and each column represents the instances in an actual class. This name is used because the matrix makes it easy to visualize if the model confused or mislabeled two classes. We compare each class with every other class and see how many samples are classified correctly or misclassified.
During the construction of this table, we come across several key metrics that are important in the field of machine learning. Let's consider a binary classification case where the output is either 0 or 1:
- True positives: These are the samples for which we predicted 1 as the output and the ground truth is 1 too.
- True negatives: These are the samples for which we predicted 0 as the output and the ground truth is 0 too.
- False positives: These are the samples for which we predicted...