Classifier (mathematics)

In mathematics, a classifier is a mapping from a (discrete or continuous) feature space X to a discrete set of labels Y.

Classifiers may either be fixed classifiers or learning classifiers, and learning classifiers may in turn be divided into supervised and unsupervised learning classifiers.

The applications of classifiers are wide-ranging. They find use in medicine (drug trial analysis, MRI data analysis), finance (share analysis, index prediction), mobile phones (signal decoding, error correction), computer vision (face recognition, target tracking), voice recognition, datamining (supermarket purchasing analysis, retail customer analysis) and uncountable other areas.

An example is a classifier that accepts a person's salary details, age, marital status, home address and credit history and classifies the person as acceptable/unacceptable to receive a new credit card or loan.

For a list of classifier applications and classifier technologies, please see statistical classification.

See also

• Artificial intelligence
• Artificial neural network
• Linear classifier
• Machine learning
• Pattern recognition
• Perceptron
• Support Vector Machine