### GREG functionalities

CLASS is mainly used for interactive look at spectra, hence its default values are all oriented towards fast plotting on screen. These defaults can be changed by command SET. If the value of a parameter is not controlled by CLASS, the command will be passed on to GREG for processing.

The following GREG presentation parameters are useful:

- SET BOX_LOCATION It can be set to LANDSCAPE, PORTRAIT, SQUARE or 4 numbers indicating the position of the box in the plot page (in centimeters).
- SET CHARACTER Size Control the size of characters in centimeters.
- SET FONT Quality Select the character quality to be used, SIMPLEX or DUPLEX. The fonts are identical to the ones used by GREG , and the character handling is the same (in command DRAW TEXT).
- SET PLOT_PAGE ... Define the page size. Warning: You will get into trouble if you want to abreviate this command to SET PLOT as SET PLOT is a valid CLASS command used to indicate whether spectra are broken lines of histograms. A way out of this is to abbreviate the GREG command as GSET PLOT.
- SET TICK Size Define the tick size in centimeters.

Note that you do not need to open a plotting window to produce a hardcopy through the HARDCOPY command. It is only much more convenient, but the plot (e.g. sequence of commands) and the way it is displayed (e.g. PS format, bitmap on a computer screen) are two completely independent things.