public int getPieIndex() {
        return this.pieIndex;
    }
    
    /**
     * Sets the pie index (this is used by the {@link MultiplePiePlot} class to 
     * track subplots).
     * 
     * @param index  the index.
     * 
     * @see #getPieIndex()
     */
    public void setPieIndex(int index) {
        this.pieIndex = index;
    }
    
    /**
     * Returns the start angle for the first pie section.  This is measured in 
     * degrees starting from 3 o'clock and measuring anti-clockwise.
     *
     * @return The start angle.
     * 
     * @see #setStartAngle(double)
     */
    public double getStartAngle() {
        return this.startAngle;