Variational Methods In Statistics

Variational methods refer to the technique of optimization in which the
object is to find the maximum or minimum of an integral involving unknown
functions. The technique is central to the study of functional analysis in the
same way that the theory of maxima and minima are central to the study of
calculus. During the last two centuries variational methods have played an
important role in the solution of many physical and engineering problems. In the
past few decades variational techniques have been developed further and have
been applied successfully to many areas of knowledge, including economics,
statistics, control theory, and operations research.