protected ResultPlot createChart(String metric){
  if (metric.equals("Approximation Set")) {
    return new ApproximationSetPlot(this,metric);
  }
 else {
    return new LinePlot(this,metric);
  }
}

protected ResultPlot createChart ( String metric ) { if ( metric . equals ( "Approximation Set" ) ) { return new ApproximationSetPlot ( this , metric ) ; } else { return new LinePlot ( this , metric ) ; } }
creates and returns the gui component for plotting the specified metric .
