Generally the user will want to run functions on all rows in a scantable. This allows very fast reduction of data. There are situations when functions should only operate on specific elements of the spectra. This is handled by the scantable cursor, which allows the user to select a single beam, IF and polarisation combination.
Example :
ASAP> scans.set_cursor(0,2,1) # beam, IF, pol ASAP> scans.smooth(allaxes=F) # in situ by default or .aipsrc