var node_echarts = require('node-echarts');
var config = {
    width: 500, // Image width, type is number.
    height: 500, // Image height, type is number.
    option: {}, // Echarts configuration, type is Object.
    //If the path  is not set, return the Buffer of image.
    path:  '', // Path is filepath of the image which will be created.
    enableAutoDispose: true  //Enable auto-dispose echarts after the image is created.
}

node_echarts(config)