/**
* Returns the y-value for the specified series and item.
*
* @param series the series (zero-based index).
* @param item the item (zero-based index).
* @return The y-value for the specified series and item.
*/
@Override
public Number getY(int series, int item) {
TimePeriodValues ts = (TimePeriodValues) this.data.get(series);
TimePeriodValue dp = ts.getDataItem(item);
return dp.getValue();
}
