Plots are useful for demonstrating the relationship
between two or more variables and frequently compare trends or data
values or depict movements of data values over time.
SAS/GRAPH uses the GPLOT procedure to produce
two-dimensional graphs that plot one or more dependent variables against
an independent variable within a set of coordinate axes. The GPLOT
procedure can display the data points as individual symbols (as in
a scatter plot). It can also use interpolation methods specified by
the SYMBOL statement to join the points. You can request spline interpolation
or regression analysis, produce various high-low charts, or generate
several other types of plots. The GPLOT procedure can also display
data as bubble plots in which circles of different sizes represent
the values of a third variable. See GPLOT Procedure for more information.

Simple line plots show
the relationship of one variable to another, often as movements or
trends in the data over a period of time. Typically, each variable
value on the horizontal axis has only one corresponding value on the
vertical axis. The line connecting data points can be smoothed using
a variety of interpolation methods, including the Lagrange and the
cubic spline interpolation methods.