How to use

getYValue

method

in

org.jfree.data.xy.VectorSeriesCollection

/**
 * Returns the y-value for an item within a series.  Note that this method
 * creates a new {@link Double} instance every time it is called---use
 * {@link #getYValue(int, int)} instead, if possible.
 *
 * @param series  the series index.
 * @param item  the item index.
 *
 * @return The y-value.
 */
@Override
public Number getY(int series, int item) {
  return new Double(getYValue(series, item));
}

/**
 * Returns the y-value for an item within a series.  Note that this method
 * creates a new {@link Double} instance every time it is called---use
 * {@link #getYValue(int, int)} instead, if possible.
 *
 * @param series  the series index.
 * @param item  the item index.
 *
 * @return The y-value.
 */
public Number getY(int series, int item) {
  return new Double(getYValue(series, item));
}