Left panel, (top) shows three 2D spectra. Two contain a spike due to spurious pixels. (Middle) resulting 2D spectrum after averaging. Spikes are no longer present, having been averaged out. (Bottom) final median 1D spectrum with no spike. Right panel, (top) shows three 2D spectra. Two contain a spike due to a spurious pixel. (Middle) resulting 1D spectra after collapse. Both spikes are passed from the 2D to 1D spectra after collapse. (Bottom) final median 1D spectrum containing the spike.