ProEssentials v7 Help .Net Reference

Chapter 6: Comparison Subsets Explained

The Graph, Scientific Graph, Polar/Smith Chart and Scatter mode of the 3D Scientific Graph object provide a comparison subset mechanism. This mechanism splits the object's subsets into two groups. The first group comprises the normal non-comparison subsets, and the second group comprises the comparison subsets. The second group's size (or quantity of comparison subsets) is controlled with either the ComparisonSubsets or RYAxisComparisonSubsets properties. Depending on which of these two properties is used, the comparison subsets will be plotted with respect to the left or right y axis. To help characterize which subsets are comparison subsets, they are plotted in a secondary plotting method PlottingMethodII. Note that the 3D Scientific Graph does not currently support a right y axis.

The benefit of using ComparisonSubsets is ease of use and a more controlled end-users interface which allows only certain logical combinations of plotting methods. However, this does limit you to two plotting methods per axis, not including annotations to this axis. For most implementations, two plotting methods along with an annotation layer per axis is plenty to suite your needs. If you need more control over plotting methods, version 5 added PlottingMethods which allows per subset control of plotting methods.

Within the demo, see example 003.

To discuss ComparisonSubset in more detail, lets look at some examples.

Example, if you have 5 subsets and set ComparisonSubsets = 2,

 Subset  Index Group  No. Non-Comparison Comparison 0 1 Non-Comparison  #1 PlottingMethod 1 1 Non-Comparison  #2 PlottingMethod 2 1 Non-Comparison  #3 PlottingMethod 3 2 Comparison #1 4 2 Comparison #2 PlottingMethodII

The comparison subsets can represent statistical quantities derived from the non-comparison data. For example, the Graph Object can include the average (mean) value of all non-comparison subsets as a comparison subset. This helps the user recognize whether any individual subset is above or below average with respect to its related information. The comparison subsets can also represent more abstract quantities. For example, a Graph object which shows yearly sales results could include comparison subsets showing the previous year's sales results.

The Graph object can automatically generate comparison subsets through the AutoStatSubsets property array. Refer to Appendix B Property Reference for more information on this property array.

Note that comparison subsets which have identical data for all points will not be included into the Graph Objects table section. They will only be included into the graph section, allowing the user to determine its value from the graphs scale. TableComparisonSubsets can be set to TRUE to disable this feature.

Some example scenarios are:

a) You need to produce a chart with one subset as a bar and one subset as a line.

 ComparisonSubsets 2 Bar Line 1

b) You need to produce a chart with three subsets as lines and two subsets as points.

 Subsets PlottingMethod PlottingMethodII ComparisonSubsets 5 Line Point 2

c) You need to produce a chart with two subsets as points and three subsets as lines and the lines are plotted with respect to the right y axis.

 Subsets PlottingMethod PlottingMethodII RYAxisComparisonSubsets 5 Point Line 3

d) You need to produce an Open/High/Low/Close chart with volume line data on the same scale.

 Subsets PlottingMethod PlottingMethodII ComparisonSubsets 5 SpecificPlotMode Line 1

Similar to ComparisonSubsets and RYAxisComparisonSubsets is TXAxisComparisonSubsets. The Scientific Graph uses this property to split the object's subsets into a different two groups. The first group is plotted with respect to the bottom x axis, and the second group is plotted with respect to the top x axis. This property has no impact on subset plotting methods.

For example, you need to produce a chart with two subsets as points and three subsets as lines and the lines are plotted with respect to the right y axis and the top x axis.

 Subsets RYAxisComparisonSubsets 5 3 3