If you have displayed a full frame image and you wish to see where the SXT
PFI region was located, you can use the routine PFI_LOC. Assuming that
the index of the image which is displayed is index, then a sample
calling sequence is:
IDL> pfi_loc, index
It is possible to use the hours keyword option to specify the number of hours plus and minus the full frame time for which you wish to have PFI locations displayed. When using STEPPER, the ``o'' option will call PFI_LOC automatically for you, taking into account any rebinning which was performed on the image.