code: function (plotX, plotY, inverted) {
  		var x = inverted ? plotY : plotX,
  			y = inverted ? plotX : plotY;
  			
  		return x >= 0 &&
  			x <= this.plotWidth &&
  			y >= 0 &&
  			y <= this.plotHeight;
  	}
docs: Check whether a given point is within the plot area
  
  @param {Number} plotX Pixel x relative to the plot area
  @param {Number} plotY Pixel y relative to the plot area
  @param {Boolean} inverted Whether the chart is inverted