Patent ID: 7640219

Claim:
An apparatus for classifying a subject data item based on a training set of pre-classified data items into a plurality of classes, wherein the subject data item and the pre-classified data items are multidimensional data items, wherein at least one dimension of the multidimensional data items represents a value having a unit of measure, the apparatus comprising: a computer system including a processor and data storage containing the subject data item and the training set, wherein the computer system is programmed to: process the training set to select a neighborhood subset of data items similar to the subject data item, wherein the neighborhood subset includes data items pre-classified into different classes; determine a set of multidimensional class representative points that each represents a corresponding class of the neighborhood subset of data items; determine a set of at least one multidimensional middle point representing at least one middle between at least two of the class representative points; for each of the at least one multidimensional middle points: define a subject vector that originates at that middle point and terminates at a multidimensional point corresponding to the subject data item; and define a set of representative vectors such that each representative vector originates at that middle point and terminates at a corresponding one of the set of multidimensional class representative points; compute at least one scalar operation between the subject vector and at least one representative vector of the set of representative vectors, wherein the at least one scalar operation takes into account an angle formed by the subject vector and the at least one representative vector; and determine a classification of the subject data item based on a result of the at least one scalar operation that takes into account the angle formed by the subject vector and the at least one representative vector, such that a result of the classification includes an association of the subject data item with at least one class of the plurality of classes.