getXValue(xCoor)

Gets the x data value given the x pixel coordinate.

Note: This method should be used only after ChartDirector has output the chart image, or after XYChart.layoutAxes, BaseChart.layout or XYChart.packPlotArea has been called. ChartDirector needs to perform auto- scaling and layout the axis before it can convert between pixel coordinates and data values.

The x data value at the x pixel coordinate.