The LAYOUT
OVERLAY statement builds a 2D, single-cell graph by overlaying the
results of the statements that are contained in the layout block.
This layout is one of several possible layout containers in GTL. Other
chapters provide detailed information on the other layout types. It
is recommended that you learn about this type of layout first, because
most of the other layout chapters contrast their feature sets with
those of the OVERLAY layout.
The outermost
layout block of any template defines the content of the graphical
area, which is represented in the following schematic:
The graph
in this next figure was defined by an OVERLAY layout with its border
turned on. The layout contains a simple scatter plot. The boundaries
of the layout container are shown by a light gray border. Everything
within this border is managed by the layout.
The OVERLAY
layout container controls
-
which statements (plot, legend,
text) can be included in the layout block
-
which statements can be combined
in the plot area bounded by the axes
-
various axis features
-
which axes are used
(there are four available: X and Y, as well X2 and Y2)
-
which axis types are
used (axis types are LINEAR, DISCRETE, LOG, and TIME )
-
axis label, axis data
range, ticks, and tick values
-
other axis features
such as offsets
-
border, padding, and background
properties
-
positioning and alignment of all
contained plots, text, legends, and nested layouts
-
default appearance of the generated
plots ( CYCLEATTRS=
option).
The layout
container also queries the contained statements for options that might
change the default internal rules for combining plots.