code: function () {
  		
  		var options = this.options,
  			chart = this.chart,
  			slicingRoom = 2 * (options.slicedOffset || 0),
  			handleSlicingRoom,
  			plotWidth = chart.plotWidth - 2 * slicingRoom,
  			plotHeight = chart.plotHeight - 2 * slicingRoom,
  			centerOption = options.center,
  			positions = [pick(centerOption[0], '50%'), pick(centerOption[1], '50%'), options.size || '100%', options.innerSize || 0],
  			smallestSize = mathMin(plotWidth, plotHeight),
  			isPercent;
  		
  		return map(positions, function (length, i) {
  			isPercent = /%$/.test(length);
  			handleSlicingRoom = i < 2 || (i === 2 && isPercent);
  			return (isPercent ?
  				// i == 0: centerX, relative to width
  				// i == 1: centerY, relative to height
  				// i == 2: size, relative to smallestSize
  				// i == 4: innerSize, relative to smallestSize
  				[plotWidth, plotHeight, smallestSize, smallestSize][i] *
  					pInt(length) / 100 :
  				length) + (handleSlicingRoom ? slicingRoom : 0);
  		});
  	}
docs: Get the center of the pie based on the size and center options relative to the
  plot area. Borrowed by the polar and gauge series types.