17. A non-transitory computer-readable medium containing instructions for controlling a data processing system to perform a method comprising: receiving a first markup document and a second markup document, both the first markup document and the second markup document containing 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.
25. The non-transitory computer-readable medium of claim 17 , wherein the characteristics include a measure of the numerical values, and wherein the method further includes: manipulating the display of the single data set using one of the tags, the tag reflecting the measure characteristic of the numerical values.