PlotSpec.setAlpha(value)

Specifies the transparency level for the Coordinate object background color or background image. The corresponding “getter” function is getAlpha().

Parameter

value: Number in range [0,1] where:
0 = completely transparent
1 = completely opaque

Example

Chart Component Script

dataset = [["State","Quantity"], ["NJ",200], ["NY",300]]; (1)
graph = new EGraph();
var elem = new IntervalElement("State", "Quantity");
elem.setHint(GraphElement.HINT_ALPHA,.8);
var sscale = new CategoricalScale("State");
var qscale = new LinearScale("Quantity");
var coord = new RectCoord(sscale,qscale);
var spec = new PlotSpec(); (2)
var logo = getImage("https://www.inetsoft.com/images/home/logo.gif");
spec.setBackgroundImage(logo);
spec.setAlpha(.3); (3)
coord.setPlotSpec(spec); (4)
graph.setCoordinate(coord);
graph.addElement(elem);

1	See dataset to use a data block instead of an array literal.
2	Create the PlotSpec object.
3	Use `setAlpha` to set the transparency.
4	Use Coordinate.setPlotSpec(spec) to assign the `PlotSpec` to the `Coordinate`.

PlotSpecSetAlpha

Script that modifies the graph or dataset properties should be placed on the Chart component itself. See Add Component Script for more information. This script has access to the Chart data and Chart API methods. Scripted Charts are not good candidates for user-modification, so you should deselect ‘Enable Ad Hoc Editing’ in the Chart Properties dialog box.

To change the property on a Chart that was previously created with the Chart Editor, use “getter” methods such as EGraph.getCoordinate() ① and Coordinate.getPlotSpec() ② to obtain a handle to the desired Coordinate and PlotSpec. For example:

var coord = graph.getCoordinate(); (1)
var spec = coord.getPlotSpec(); (2)
// Compact syntax: var spec = graph.getCoordinate().getPlotSpec();

spec.setAlpha(0.5);