ARCHETYPAL ANALYSIS

Archetypal analysis represents each individual in a data set as a mixt ure of individuals of pure type or archetypes. The archetypes themselv es are restricted to being mixtures of the individuals in the data set . Archetypes are selected by minimizing the squared error in represent ing each individual as a mixture of archetypes. The usefulness of arch etypal analysis is illustrated on several data sets. Computing the arc hetypes is a nonlinear least squares problem, which is solved using an alternating minimizing algorithm.