Property arrays are properties like YData,
SubsetLabels, and PointColors
that have multiple values defined by one or two indices. These property
arrays are dynamic in that they grow as you increase the indices used
to set items.
Some property arrays have default elements defined and others are empty
by default. Some examples of property arrays with default elements are
and SubsetColors. Some examples
of property arrays empty by default are RandomSubsetsToGraph, SubsetsToLegend,
and MultiAxesSubsets. It is important to realize that a property array
has a size and this size is often used to control image construction.
If you are providing some form of custom user interface or report procedure,
you may be continuously manipulating property arrays. If they grow dynamically,
you also need a way to shrink or empty the property array. This can be
accomplished by setting the index to (-1) or in the case of a two dimensional
property array (0,-1), and equating this to the new size.
For example, RandomSubsetsToGraph is a common property array that needs
to be emptied or resized. The following code shows how to empty this property
Integer property arrays are emptied as follows:
PEGraph1.RandomSubsetsToGraph[-1] := 0;
Two dimensional property arrays are emptied like:
PEGraph1.YData[0, -1] := 0;
String property arrays are emptied like:
PEGraph1.PointLabels[-1] := '0';
Also note that PEactions = REVERT_TO_DEFAULTS (20) which calls PEreset
will empty the graph of all property settings and revert the object to
its default state. This is easier and the recommended approach when you
need to reset the state of the object due to repeatedly changing the object.