Creates a two-dimensional
plot that represents the values of three variables. Generating an
X, Y grid of rectangles from the values of two independent variables,
it colors the rectangles to represent the values of a third variable,
which can be a response variable or a group variable.
The following syntax
is used when the colors are determined by a grouping variable:
The following syntax
is used when the colors are determined by a response variable that
has continuous, numeric values: