1. A computer-based method of ordering categorical values of one or more attributes associated with a data set, the method comprising the steps of: obtaining the categorical values of the one or more attributes associated with the data set; forming a task of ordering the categorical values of the one or more attributes associated with the data set as a continuous optimization ordering problem; computing at least one continuous ordering solution to the continuous optimization ordering problem; and making at least a portion of the computed continuous ordering solution available for use in accordance with a data visualization system.