var myChart = echarts.init(document.getElementById('main')),
        option = {
            tooltip: {},
            legend: {},
            series: [{
                name: '访问来源',
                type: 'pie',
                radius: '55%',
                center: ['50%', '60%'],
                data: [],
                itemStyle: {
                    emphasis: {
                        shadowBlur: 10,
                        shadowOffsetX: 0,
                        shadowColor: 'rgba(0, 0, 0, 0.5)'
                    }
                }
            }]
        };
    myChart.setOption(option);

    //以下为ajax获取到的数据
    var data = [{
            value: 335,
            name: '直接访问'
        }, {
            value: 310,
            name: '邮件营销'
        }, {
            value: 234,
            name: '联盟广告'
        }, {
            value: 135,
            name: '视频广告'
        }, {
            value: 1548,
            name: '搜索引擎'
        }],
        legends = []
    data.forEach(function(e, i) {
        legends.push(e.name)
    })
    myChart.setOption({
        legend: {
            data: legends
        },
        series: [{
            data: data
        }]

    });