public boolean removeTrace(final Trace trace){
  boolean result=traceList.remove(trace);
  if (result) {
    remove(trace);
    revalidate();
  }
  return result;
}

public boolean removeTrace ( final Trace trace ) { boolean result = traceList . remove ( trace ) ; if ( result ) { remove ( trace ) ; revalidate ( ) ; } return result ; }
remove a trace from the plot area .
