1. A computer-implemented method comprising: recording coordinate values representing a two-dimensional pattern as a three-dimensional pattern, including storing x-coordinate and y-coordinate values in conjunction with a z-coordinate, the z-coordinate having a first value at times when the pattern is being entered and a second value at times when the pattern is not being entered; fitting the x-coordinate, y-coordinate and z-coordinate values at sample points to a plurality of related mathematical basis functions by transforming the coordinate values at the sample points into coefficients of the function; featurizing the input pattern into a plurality of features, at least some of the features corresponding to the coefficients of the basis function; and performing computerized recognition by using the features to determine an alphanumeric value corresponding to the input pattern.