1. A method in a data processing system, comprising the steps of: receiving a first markup document and a second markup document, both the first markup document and the second markup document including numerical values and tags reflecting characteristics of the numerical values, wherein the characteristics indicate that the numerical values of the first markup document differ in format from the numerical values of the second markup document; automatically transforming the numerical values of at least one of the first markup document and the second markup document, so that the numerical values of the first markup document and the second markup document have a common format; combining the first markup document and the second markup document into a single data set; and displaying the single data set.