By ``one dimensional data'' we mean any distribution of (X,Y) data points. This obviously includes functions Y=f(X) and X=f(Y), but also more general cases. Plotting such kind of data is the simplest thing GREG can do. This can be done basically in four modes :

- The broken line mode using command
`CONNECT`, in which data points are simply connected by straight lines. Note that data must be ordered. - The curve mode using command
`CURVE`, in which the data is interpolated to produce a smooth aspect. Again, the data must be adequately sorted. - The histogram mode using command
`HISTOGRAM`. As above, data must be ordered. Note that this capability is restricted to functions Y=f(X). - The marker mode using command
`POINTS`, in which a graphic marker is plotted at each data point. The size of the markers may depend on values in the Z buffer. Contrary to the other commands, the data need not be ordered at all.

In addition to these four commands, the command `ERRORBAR` which uses
the Z buffer to define errors may also be relevant to one-dimensional data.
A facility to sort data by ascending order is given by means of command
`SORT`.

All these commands belong to the so-called ``GREG1'' language (in the SIC meaning) ; this language also includes all the utility functions of GREG such as pen definitions, annotations, coordinate conversions, etc...