Oops, perhaps I should have said ?a representative sample of the data? but it looks like it has arrived safely. Let me tell you about head() someday. I am not sure of the data.frame names since the original code has some sub-setting at the beginning. At the moment I am calling the first data set ?mortdata? and the second one ?tempdata? but is this correct? Your wording seems a bit ambiguous. It seems to run so I guess I have the data sets named correctly. Now we just hope someone with domain knowledge show up to discuss the actual problem. I killed the rest of the post as it was a bit too big to keep sending back and forth. John Kane Kingston ON ____________________________________________________________ FREE 3D EARTH SCREENSAVER - Watch the Earth right on your desktop!