function removeRect(dataIndex, animationModel, el) {
	        // Not show text when animating
	        el.style.text = '';
	        graphic.updateProps(el, {
	            shape: {
	                width: 0
	            }
	        }, animationModel, dataIndex, function () {
	            el.parent && el.parent.remove(el);
	        });
	    }
@param {Object} opt
@param {module:echarts/coord/Axis} opt.axis Only support category axis currently.
@param {number} opt.count Positive interger.
@param {number} [opt.barWidth]
@param {number} [opt.barMaxWidth]
@param {number} [opt.barGap]
@param {number} [opt.barCategoryGap]
@return {Object} {width, offset, offsetCenter} If axis.type is not 'category', return undefined.