Plotting spectra is controlled by several parameters:

`SET UNIT``Type`defines the unit of the X axis, which may be C (for Channel number), V (for Velocity), F (for Frequency) or I (for Image).`SET PLOT``Type`defines the plotting type`PLOT`(Normal or Histogram); Normal gives straight lines connecting the data points (this is the default since it is faster). Histogram gives a more realistic representation of spectroscopic data.`SET MODE``X (or Y) Type`defines the plotting limits in X or Y, where type stands for`TOTAL`(all channels plotted in X, complete scale in Y),`AUTO`(take the plotting limits in use when the spectrum was last written), or two numbers for fixed limits; X or Y specify the axis on which the type is to apply. For X axis, the limits are in the current units (C, V or F). For F, specify the offset from the rest frequency in MHz (note: the caption and the numbers on the axis will refer to absolute rest frequencies).