I have a question which somebody may be able to help answer; I have alot of numerical data (4 sig. figs) in lists, of different lengths, which I would like to compare with one and other. The data currently resides in Microsoft Excel but I can move it anywhere, and the file size is minimal. I would like to compare the lists at 1, 2, 3 and 4 sig. figs. and acquire an output of matches between lists. I have been told that Perl as a programming language is very novice friendly and please phrase all replies with this in mind.