有向无环图echarts graph配置项内容和展示

在画布可缩放拖拽的情况下，如何使指定的节点出现到画布的正中央位置

      optionData = [{"x":0,"y":0,"name":"bce_topic_1","value":1},{"x":0,"y":-1,"name":"bce_topic_2","value":2},{"x":0,"y":-2,"name":"bce_topic_3","value":3},{"x":1,"y":-2,"name":"bce_topic_4","value":4},{"x":1,"y":-5,"name":"bce_topic_5","value":5},{"x":1,"y":-4,"name":"bce_topic_6","value":6},{"x":3,"y":-3,"name":"bce_topic_7","value":7},{"x":2,"y":-1,"name":"bce_topic_8","value":8},{"x":3,"y":0,"name":"bce_topic_9","value":9},{"x":4,"y":-2,"name":"bce_topic_10","value":10},{"x":5,"y":-1,"name":"bce_topic_11","value":11},{"x":4,"y":0,"name":"bce_topic_12","value":12},{"x":5,"y":0,"name":"bce_topic_13","value":13},{"x":4,"y":-1,"name":"bce_topic_14","value":14}];
optionLinks = [{"source":"bce_topic_1","target":"bce_topic_2"},{"source":"bce_topic_1","target":"bce_topic_8"},{"source":"bce_topic_9","target":"bce_topic_8"},{"source":"bce_topic_9","target":"bce_topic_7"},{"source":"bce_topic_14","target":"bce_topic_10"},{"source":"bce_topic_13","target":"bce_topic_10"},{"source":"bce_topic_13","target":"bce_topic_11"},{"source":"bce_topic_2","target":"bce_topic_3"},{"source":"bce_topic_2","target":"bce_topic_4"},{"source":"bce_topic_8","target":"bce_topic_4"},{"source":"bce_topic_10","target":"bce_topic_7"},{"source":"bce_topic_4","target":"bce_topic_6"},{"source":"bce_topic_7","target":"bce_topic_6"},{"source":"bce_topic_6","target":"bce_topic_5"},{"source":"bce_topic_12","target":"bce_topic_14"},{"source":"bce_topic_11","target":"bce_topic_4"}];

option = {
        title: {
            text: '有向无环图'
        },
        tooltip: {},
        animationDurationUpdate: 1500,
        animationEasingUpdate: 'quinticInOut',
        series : [
            {
                type: 'graph',
                layout: 'none',
                symbol: 'rect',
                symbolSize: [140, 20],
                roam: true,
                label: {
                    normal: {
                        show: true
                    }
                },
                edgeSymbol: ['none', 'arrow'],
                data: optionData,
                links: optionLinks,
                lineStyle: {
                    normal: {
                        opacity: 0.9,
                        width: 2,
                        curveness: 0
                    }
                }
            }
        ]
    };