Summary

Go over a summary of what we have learned in this chapter.

In this chapter, we learned about the following concepts.

Multiclass logistic regression classification

  • Logistic regression is one of the most popular and widely used classification algorithms, and by default, it is limited to a binary class classification problem. However, logistic regression can be used for multiclass classification using extensions like OVR and multinomial.

    • In OVR, the problem is first transformed into multiple binary classification problems, and under the hood, separate binary classifiers are trained for all classes.

    • In multinomial, the solvers learn an accurate multinomial logistic regression model. In this case, the probability estimates should be better calibrated than OVR. The cross-entropy error/loss function supports multiclass classification ...