RiskMapPlotTableDataModel: Basic Plots

The main responsibility of a RiskMapPlotTableDataModel is to determine which data variables are used in the risk map and what role each variable plays. The primary roles are

XVariable

Assigns a plot's X variable, whose values are represented along the horizontal axis.

YVariable

Assigns a plot's Y variable, whose values are represented along the left vertical axis.

Each of these primary roles are assigned to a PlotVariable. A unique plot element (marker) is produced for each unique X,Y value pair or combination of value pairs when other variable roles are specified.

For example, the following code fragment assigns the X and Y variable roles to variables named "Systolic Blood Pressure" and "Blood Sugar":

 
// Create a data source
   javax.swing.table.TableModel dataTable = <...>;

// Create a data model and attach the data source to it
   RiskMapPlotTableDataModel dataModel =
     new RiskMapPlotTableDataModel();
   dataModel.setModel(dataTable);
     
// Assign the X and Y variable roles. Assignments
// assume the data source contains these variables.
   dataModel.setXVariable(new PlotVariable("Systolic Blood Pressure"));
   dataModel.setYVariable(new PlotVariable("Blood Sugar"));

// Set up the desired risk map, in this case, a SimpleRiskMap
   SegmentedRangeModel xRange = SegmentedRangeModel.
     newSegmentedRangeModel(new double[]{0, 120, 135, 160, 200});
   SegmentedRangeModel yRange = SegmentedRangeModel.
     newSegmentedRangeModel(new double[]{0, 100, 120, 160, 400});

   SimpleRiskMap simpleRiskMap = new SimpleRiskMap(xRange, yRange,
     new Color[]{Color.GREEN,Color.YELLOW, Color.ORANGE, Color.RED},
     SimpleRiskMap.TYPE_BLOCK);

// Construct a RiskMapPlot that uses the data model and risk map
   RiskMapPlot riskMapPlot = new RiskMapPlot(dataModel);
   riskMapPlot.getGraphModel().setRiskMap(simpleRiskMap);

RiskMapPlotTableDataModel: Plot Markers

The ShapeVariable, SizeVariable, and ColorVariable roles can be used to control the shape, size, and color of the markers in any RiskMapPlot. These roles are assigned to Variables, and the assignment would resemble the following:

 
dataModel.setColorVariable(new Variable("CMarker"));

The variables that are assigned these roles must have the appropriate information. For example, a variable that is assigned the Color role must store valid color values.

As an alternative to using a variable role to change plot markers, you can use a plot's RiskMapPlotModel to

• assign a MarkerStyle to the markers
• group markers and lines by calling the setStyleBy() method
• hide markers by calling the setMarkerEnabled() method with the argument value false.

RiskMapPlotTableDataModel: Labels for Plot Points

To label plot points, use the BottomMarkerLabelVariable or TopMarkerLabelVariable roles. Either role can be assigned to a data column that is used for X or Y variables in the program code. In the following code fragment, the values from a data column named Year are used to label plot points above the plot markers:

 
dataModel.setTopMarkerLabelVariable(new Variable("Year"));

RiskMapPlotTableDataModel: Data Groups

To identify data groups according to the values of a ClassificationVariable, assign the GroupVariable role to the appropriate classification variable.

For example, a variable named Patient might be assigned the Group role so that the plot markers reveal which points came from a data row with patient names. The assignment would resemble the following:

 
dataModel.setGroupVariable(new ClassificationVariable("Patient"));

Markers of different shape and color are used to represent each unique value of the Group variable.

RiskMapPlotTableDataModel: Valid Variable Roles

The following table summarizes the RiskMapPlotTableDataModel variable roles and the type of data each role supports.

Variable Role	Class Type
XVariable* Assigns horizontal-axis variable	PlotVariable
YVariable* Assigns left vertical-axis variable	PlotVariable
AuxiliaryVariable Array of variables that are not represented in the chart but are included among the variables that are passed in the events on the RiskMapPlot data elements	Variable[]
BottomMarkerLabelVariable Assigns labels below the plot markers	Variable
ColorVariable Assigns marker colors	Variable
ColumnVariable Aligns multiple charts in columns	ClassificationVariable
DataTipVariable Array of variables whose values will be displayed in the data tips	Variable[]
GroupVariable Associates markers with data groups	ClassificationVariable
RowVariable Aligns multiple charts in rows	ClassificationVariable
ShapeVariable Assigns marker shapes	Variable
SizeVariable Assigns marker sizes	Variable
SortVariable Defines the order in which plot points are connected when a line interpolation is applied	Variable
TopMarkerLabelVariable Assigns labels below the plot markers	Variable
* required variable

RiskMapPlotTableDataModel: Behavior

To generate a graph, a RiskMapPlot needs data columns for the X and Y variable roles.

If the Y role is not assigned in the program code, a RiskMapPlot selects the first numeric column found in the RiskMapPlotTableDataModel and uses it as its Y variable. If there is no numeric column in the data, then it selects the first string column.

If the X role is not assigned in the program code, a RiskMapPlot selects the first numeric column which is different from Y and uses it as the X variable. If no valid numeric column is found, then it selects the first string column different from Y and uses it as X.

This default behavior occurs only when the X and/or Y role is not assigned. If either role is assigned to a variable that does not exist in the data, the RiskMapPlot cannot display a graph.

RiskMapPlotTableDataModel: Events

A RiskMapPlotTableDataModel fires property change events when

• any of its properties are changed
• any property in a contained model is modified.

For example, if the name property is changed in the PlotVariable that has been assigned the XVariable role, the RiskMapPlotTableDataModel fires a ProeprtyChangeEvent stating that the XVariable has changed.

RiskMapPlotTableDataModel: Error Handling

When variable roles are assigned, the RiskMapPlotTableDataModel does not confirm that the variables exist in the TableModel. Thus, assigning a non-existent data column to a variable role may mean that the RiskMapPlot cannot display a graph. For example, if the XVariable role is assigned to a Product column but the TableModel does not contain a Product column, then the RiskMapPlot fails to produce a graph.

If the XVariable and YVariable roles are correctly assiged to existing variables but another role is incorrectly assigned, the RiskMapPlot displays a graph without the incorrect role. For example, if the XVariable and YVariable roles are correctly assigned but the ColumnVariable role is not, a graph using the X and Y roles is generated, but the Column role is ignored.