 A linear classifier is often used in situations where the speed of classification is an issue, since it is often the fastest classifier, especially when formula_1 is sparse.Also, linear classifiers often work very well when the number of dimensions in formula_1 is large, as in document classification, where each element in formula_1 is typically the number of occurrences of a word in a document (see document-term matrix).In such cases, the classifier should be well-regularized.