Declaration: GetSpectrum(ix, iy, TimeSlot, Group: integer; var Spectrum: TDoubleArray): integer;
Retrieves the spectrum at the pixel position [ix,iy] at the time specified by the parameter TimeSlot and copies the data into the dynamic array Spectrum. The size of the array Spectrum is automatically adjusted to hold the entire spectrum. The parameter Group specifies which spectrum to retrieve (valid range of values is 1 to 4, see spectral groups). The function returns the following error codes:
 0 ... everything is OK
-1 ... no such group
-2 ... ix, iy, or timeslot are out of range