`DIVIDE`makes the ratio of the`R`and`T`spectra. The two spectra must have the same velocity scale.`FFT`plots the power spectrum of the current observation. It might help identify spurious ripples. Editing of the fourier transform is possible, so that these ripples may be suppressed.`NOISE`generates a Gaussian noise as intense as in the current spectrum using the rms value determined by the`BASE`command, or using a rms value given as an argument.`NOISE Value NEW`will create a noisy spectrum of given noise level into`R`, after copying`R`in`T`.`RESAMPLE`resamples the`R`spectrum on the specified grid. If the final sampling is coarser than the original one, a smoothing occurs to the final sampling.`SMOOTH`operates a Hanning smoothing by default and divide the number of channels by two. Other arguments can be specified to use other methods.`SMOOTH AUTO`uses a sophisticated variable-resolution algorithm, but it requires the channels to be really independent and this is apparently seldom the case in radio astronomy.`SMOOTH GAUSS Width`convolves the spectrum by Gaussian of given Width in current units; it does not take care of bad channels.`SMOOTH BOX N`make the average of N adjacent channels and divides the number of channels by N.