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IGB allows you to work with 2 graph tracks at a time. The first track selected will be given a temporary label of 'A'. Shift click selection of the second track will give it the temporary label 'B'. After the two tracks have been selected, you choose the mathematical function from the four buttons:
IGB will open an new track for the newly created graph. It will be titled as the name of the function performed, and then each of the original tracks in parenthesis. The new track can be adjusted for style and display just as any other graph track.
Note: IGB will not display negative or fractional numbers, only positive integers. Keep this in mind when you designate which graph tracks will be 'A' and 'B'.