echarts如何禁用自动调整echarts graph配置项内容和展示

echarts在增加、删除界面元素的时候图片会自行拉伸，我这边有一个项目拓扑图会比较大，有没有办法禁用掉echarts的自动拉伸，让用户通过拖拽滚动条的方式浏览整个拓扑图

      option = {
    title: {
        text: ''
    },
    tooltip: {},
    animationDurationUpdate: 1500,
    animationEasingUpdate: 'quinticInOut',
    series : [
        {
            type: 'graph',
            layout: 'none',
            symbolSize: 50,
            roam: true,
            label: {
                normal: {
                    show: true
                }
            },
            edgeSymbol: ['circle', 'arrow'],
            edgeSymbolSize: [4, 10],
            edgeLabel: {
                normal: {
                    textStyle: {
                        fontSize: 20
                    }
                }
            },
            data: [{
                name: '节点1',
                x: 300,
                y: 300
            }, {
                name: '节点2',
                x: 800,
                y: 300
            }, {
                name: '节点3',
                x: 550,
                y: 100
            }, {
                name: '节点4',
                x: 550,
                y: 500
            }],
            // links: [],
            links: [{
                source: 0,
                target: 1,
                symbolSize: [5, 20],
                label: {
                    normal: {
                        show: true
                    }
                },
                lineStyle: {
                    normal: {
                        width: 5,
                        curveness: 0.2
                    }
                }
            }, {
                source: '节点2',
                target: '节点1',
                label: {
                    normal: {
                        show: true
                    }
                },
                lineStyle: {
                    normal: { curveness: 0.2 }
                }
            }, {
                source: '节点1',
                target: '节点3'
            }, {
                source: '节点2',
                target: '节点3'
            }, {
                source: '节点2',
                target: '节点4'
            }, {
                source: '节点1',
                target: '节点4'
            }],
            lineStyle: {
                normal: {
                    opacity: 0.9,
                    width: 2,
                    curveness: 0
                }
            }
        }
    ]
};;