LDA and QDA for Classification
Discriminant analysis encompasses methods that can be used for both classification and dimensionality reduction. Linear discriminant analysis (LDA) is particularly popular because it is both a classifier and a dimensionality reduction technique. Despite its simplicity, LDA often produces robust, decent, and interpretable classification results. When tackling real-world classification problems, LDA is often the first and benchmarking method before other more complicated and flexible ones are employed. Quadratic discriminant analysis (QDA) is a variant of LDA that allows for non-linear separation of data.
...