Echarts多柱状图,隐藏所有图例后,x轴刻度只显示一个点

描述:当前是关于Echarts图表中的 柱状图 示例。
 
            option = {
					title: {
					  text: 'Graph title',
					  subtext: 'Graph Sub-text'
					},
					tooltip: {
					  trigger: 'axis'
					},
					legend: {
					  data: ['sales', 'purchases']
					},
					toolbox: {
					  show: false
					},
					calculable: true,
					xAxis: [{
					  type: 'category',
					  data: ['1?', '2?', '3?', '4?', '5?', '6?', '7?', '8?', '9?', '10?', '11?', '12?']
					}],
					yAxis: [{
					  type: 'value'
					}],
					series: [{
					  name: 'sales',
					  type: 'bar',
					  data: [2.0, 4.9, 7.0, 23.2, 25.6, 76.7, 135.6, 162.2, 32.6, 20.0, 6.4, 3.3],
					  markPoint: {
						data: [{
						  type: 'max',
						  name: '???'
						}, {
						  type: 'min',
						  name: '???'
						}]
					  },
					  markLine: {
						data: [{
						  type: 'average',
						  name: '???'
						}]
					  }
					}, {
					  name: 'purchases',
					  type: 'bar',
					  data: [2.6, 5.9, 9.0, 26.4, 28.7, 70.7, 175.6, 182.2, 48.7, 18.8, 6.0, 2.3],
					  markPoint: {
						data: [{
						  name: 'sales',
						  value: 182.2,
						  xAxis: 7,
						  yAxis: 183,
						}, {
						  name: 'purchases',
						  value: 2.3,
						  xAxis: 11,
						  yAxis: 3
						}]
					  },
					  markLine: {
						data: [{
						  type: 'average',
						  name: '???'
						}]
					  }
					}]
				  };