### Single spectrum

Single spectrum are usually plotted using the following commands:

- BOX, which plots the frame. The Y axes are labelled in temperature units; the X axes may be in the following units: Velocity, Frequency, Image frequency, or Channel number. The upper X axis may be labelled in a different unit than that of the lower axis. Units for both axes are entered by the command SET UNIT L U, where L and U stand for the units of lower and upper axes and may be any of V, F, I, or C. The second parameter U is optional; if not entered, it defaults to L.

  BOX accepts the option /UNIT which specifies a unit temporarily different from the current one (given by the SET UNIT command). The parameter UPPER will modify only the unit for the upper axis of the frame. For instance: BOX /UNIT F UPPER will give velocities on the lower axis (if this is the current unit specified by SET UNIT V) and rest frequencies on the upper axis.

- SPECTRUM, which plots the spectrum, in the current mode, clipped into the current box. An offset may be given as argument to plot two spectra above each other for comparison.
- TITLE, which writes a header above the frame. The title format is controlled by the SET FORMAT command.
- PLOT, which performs all of CLEAR; BOX; SPECTRUM; TITLE in a single operation.