Problem: I loaded an UNSMRY file and a .hist file and tried to make a comparison plot with them. If the UNSMRY file is the active file, then RS2010 shows a plot but no comparison, and if the .hst file is the active file then RS2010 does show a comparison plot. Why does RS2010 not show a comparison plot when the UNSMRY file is active?
Solution: This can happen if the two datasets have differing variable lists. When one of the two datasets is active and plotted on the screen RS2010 will look at the variable list in the other dataset and try to find the same variables that are already plotted on the screen. If it finds them it will make a comparison plot.
This means that if RS2010 is not making a comparison plot, you need to check the variables shown on the plot, and make sure that these variables exist in both files.
Please note that to RS2010, a DATE variable is different than a TIME variable, and RS2010 does not automatically convert between the two.