0๐
var myChartCompleted = this.$echarts.init(this.$refs.Finish);
myChartCompleted.setOption(this.optionCompleted)
myChartCompleted._dom.childNodes[0].childNodes[0].style.height="290px"
myChartCompleted._dom.childNodes[0].childNodes[0].style.width="180px"
You can use this method to get the DOM node of the canvas used by echarts and assign values to its properties. If you want to manipulate other properties of it, you can print this node and see ๐ (Google Translate)
Source:stackexchange.com