echart 3 数据密集时，断点不显示问题

如上图最开始标识的两点是不显示的，配置处理代码如下（series中配置symbolSize: 1,showAllSymbol: true）：

myChart.showLoading();
$.get('data/asset/data/confidence-band.json', function (data) {
    myChart.hideLoading();

    var base = -data.reduce(function (min, val) {
        return Math.floor(Math.min(min, val.l));
    }, Infinity);
    myChart.setOption(option =
        {
    "title": {
        "codedata": "ERAB.NbrSuccEstab/ERAB.NbrAttEstab",
        "x": "left",
        "y": -10,
        "subtextStyle": {
            "fontSize": 12,
            "color": "#CAC5D4"
        }
    },
    "tooltip": {
        "trigger": "axis"
    },
    "grid": {
        "top": "72px",
        "bottom": "32px"
    },
    "legend": {
        "data": [
            "32UE_OFFICE(192.168.3.111)"
        ]
    },
    "xAxis": [
        {
            "type": "category",
            "boundaryGap": true,
            "data": [
                "2017-10-12 00:00:00",
                "2017-10-12 00:15:00",
                "2017-10-12 00:30:00",
                "2017-10-12 00:45:00",
                "2017-10-12 01:00:00",
                "2017-10-12 01:15:00",
                "2017-10-12 01:30:00",
                "2017-10-12 01:45:00",
                "2017-10-12 02:00:00",
                "2017-10-12 02:15:00",
                "2017-10-12 02:30:00",
                "2017-10-12 02:45:00",
                "2017-10-12 03:00:00",
                "2017-10-12 03:15:00",
                "2017-10-12 03:30:00",
                "2017-10-12 03:45:00",
                "2017-10-12 04:00:00",
                "2017-10-12 04:15:00",
                "2017-10-12 04:30:00",
                "2017-10-12 04:45:00",
                "2017-10-12 05:00:00",
                "2017-10-12 05:15:00",
                "2017-10-12 05:30:00",
                "2017-10-12 05:45:00",
                "2017-10-12 06:00:00",
                "2017-10-12 06:15:00",
                "2017-10-12 06:30:00",
                "2017-10-12 06:45:00",
                "2017-10-12 07:00:00",
                "2017-10-12 07:15:00",
                "2017-10-12 07:30:00",
                "2017-10-12 07:45:00",
                "2017-10-12 08:00:00",
                "2017-10-12 08:15:00",
                "2017-10-12 08:30:00",
                "2017-10-12 08:45:00",
                "2017-10-12 09:00:00",
                "2017-10-12 09:15:00",
                "2017-10-12 09:30:00",
                "2017-10-12 09:45:00",
                "2017-10-12 10:00:00",
                "2017-10-12 10:15:00",
                "2017-10-12 10:30:00",
                "2017-10-12 10:45:00",
                "2017-10-12 11:00:00",
                "2017-10-12 11:15:00",
                "2017-10-12 11:30:00",
                "2017-10-12 11:45:00",
                "2017-10-12 12:00:00",
                "2017-10-12 12:15:00",
                "2017-10-12 12:30:00",
                "2017-10-12 12:45:00",
                "2017-10-12 13:00:00",
                "2017-10-12 13:15:00",
                "2017-10-12 13:30:00",
                "2017-10-12 13:45:00",
                "2017-10-12 14:00:00",
                "2017-10-12 14:15:00",
                "2017-10-12 14:30:00",
                "2017-10-12 14:45:00",
                "2017-10-12 15:00:00",
                "2017-10-12 15:15:00",
                "2017-10-12 15:30:00",
                "2017-10-12 15:45:00",
                "2017-10-12 16:00:00",
                "2017-10-12 16:15:00",
                "2017-10-12 16:30:00",
                "2017-10-12 16:45:00",
                "2017-10-12 17:00:00",
                "2017-10-12 17:15:00",
                "2017-10-12 17:30:00",
                "2017-10-12 17:45:00",
                "2017-10-12 18:00:00",
                "2017-10-12 18:15:00",
                "2017-10-12 18:30:00",
                "2017-10-12 18:45:00",
                "2017-10-12 19:00:00",
                "2017-10-12 19:15:00",
                "2017-10-12 19:30:00",
                "2017-10-12 19:45:00",
                "2017-10-12 20:00:00",
                "2017-10-12 20:15:00",
                "2017-10-12 20:30:00",
                "2017-10-12 20:45:00",
                "2017-10-12 21:00:00",
                "2017-10-12 21:15:00",
                "2017-10-12 21:30:00",
                "2017-10-12 21:45:00",
                "2017-10-12 22:00:00",
                "2017-10-12 22:15:00",
                "2017-10-12 22:30:00",
                "2017-10-12 22:45:00",
                "2017-10-12 23:00:00",
                "2017-10-12 23:15:00",
                "2017-10-12 23:30:00",
                "2017-10-12 23:45:00",
                "2017-10-13 00:00:00"
            ],
            "splitLine": {
                "show": false
            },
            "name": "Hour"
        }
    ],
    "yAxis": [
        {
            "name": "(%)",
            "type": "value",
            "axisLabel": {
                "formatter": "{value}"
            },
            "min": 0
        }
    ],
    "series": [
        {
            "name": "32UE_OFFICE(192.168.3.111)",
            "type": "line",
            symbolSize: 1,
            showAllSymbol: true,
            "data": [
                null,
                "",
                "",
                "",
                "",
                "",
                "",
                90,
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                70,
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                "",
                100,
                100,
                100,
                "",
                "",
                "",
                "",
                "",
                "",
                null,
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                null,
                null,
                null,
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                null,
                null,
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                null,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                null,
                null
            ]
        }
    ]
}
    );
});