The algebraic essentials of EOF analysis can be described as follows. Let be surface temperature or other climatic variables at point in any given area of the globe at time .Suppose this measurement be taken over the set of locations at time . Thus the snapshots referred to above are collections of reading taken at each of the times , and are centered on their time averages. It can be thought these collection as (i.e., column) vectors forming a swarm of points about the origin of a -dimensional Euclidian space . The symbol “T” denotes the transpose operation. These collections can also be placed into a matrix.