protected void selectAutoTickUnit(Graphics2D g2,Rectangle2D dataArea,RectangleEdge edge){
  if (RectangleEdge.isTopOrBottom(edge)) {
    selectHorizontalAutoTickUnit(g2,dataArea,edge);
  }
 else   if (RectangleEdge.isLeftOrRight(edge)) {
    selectVerticalAutoTickUnit(g2,dataArea,edge);
  }
}

protected void selectAutoTickUnit ( Graphics2D g2 , Rectangle2D dataArea , RectangleEdge edge ) { if ( RectangleEdge . isTopOrBottom ( edge ) ) { selectHorizontalAutoTickUnit ( g2 , dataArea , edge ) ; } else if ( RectangleEdge . isLeftOrRight ( edge ) ) { selectVerticalAutoTickUnit ( g2 , dataArea , edge ) ; } }
selects an appropriate tick value for the axis . the strategy is to display as many ticks as possible ( selected from an array of ' standard ' tick units ) without the labels overlapping .
