When you
write GTL programs, all axes are automatically managed for you. For
example, in a LAYOUT OVERLAY block, the overlay container decides
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-
the axis type of each axis (linear,
time, ...)
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the data range of each axis
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other axis characteristics, some
of which are derived from the current style.
Usually,
the internal techniques that are used to manage axes produce good
default axes. Occasionally, you might find some feature you want to
change. Layout statements provide many axis options that change the
default axis behavior. This chapter shows how axes are managed by
default and the programming options that are available to you for
changing that behavior.
Note: This chapter
discusses axis features that are specific to an OVERLAY layout when
it is the outermost layout and not nested in another layout. Nesting
layouts sometimes causes interactions that affect the axis features.
You should read this chapter before reading about other layout types
because this chapter provides the basic principles of axis management.
Be aware, though, that the other layout types (for example, OVERLAYEQUATED,
OVERLAY3D, LATTICE, DATAPANEL and DATALATTICE) also control axes.
Many of these layouts have similar although not identical options
to the OVERLAY layout. See the chapters on these other layouts for
detailed discussions on how they manage axes.