code: protected void paintTick(Graphics g, ValueDimension dim, Number tickValue, int tickLength) {
  		String str = String.format(getTickInfo(dim).getFormat(), tickValue.doubleValue());
  		int xPosition;
  		int yPosition;
  		Point descPos;
  		switch (dim) {
  		case X:
  			xPosition = getXFor(tickValue);
  			yPosition = getPaintingRegion().getBottomLeft().y;
  			g.drawLine(xPosition, yPosition, xPosition, yPosition+tickLength);
  			descPos = getPaintingRegion().getDescriptionPos(dim, str, xPosition);
  			g.drawString(str, descPos.x, descPos.y+tickLength);
  			break;
  		case Y:
  			xPosition = getPaintingRegion().getBottomLeft().x;
  			yPosition = getYFor(tickValue);
  			g.drawLine(xPosition, yPosition, xPosition-tickLength, yPosition);
  			descPos = getPaintingRegion().getDescriptionPos(dim, str, yPosition);
  			g.drawString(str, descPos.x-tickLength, descPos.y+tickLength);
  			break;
  		}
  	}
docs: Paints a tick with the specified length and value with respect to the given dimension.
  @param g Graphics context
  @param dim Reference dimension for tick painting
  @param tickValue Value for the tick
  @param tickLength Length of the tick