javascript - 如何在谷歌折线图中按年份分隔日期

Question

我有一个日期/值列表，我想在 Google Charts: Line Chart 中显示.

    data.addRows([
        [new Date("2011-02-01T15:18:21+00:00"), 21.77],
        [new Date("2011-03-01T15:18:59+00:00"), 20.96],
        //[...],
        [new Date("2011-12-01T07:54:15+00:00"), 17.04],
        [new Date("2012-01-01T10:29:00+00:00"), 20.43],
        [new Date("2012-02-01T08:03:00+00:00"), 22.51],
        [new Date("2012-03-01T08:07:00+00:00"), 26.75],
        //[...],
        [new Date("2013-01-02T16:16:00+00:00"), 20.7],
        [new Date("2013-02-03T13:51:00+00:00"), 24.41],
        [new Date("2013-03-01T08:06:00+00:00"), 25.44],
        //[...],
        [new Date("2014-01-01T10:19:00+00:00"), 16.24],
        [new Date("2014-02-01T10:16:00+00:00"), 19.13],
        [new Date("2014-03-01T08:05:00+00:00"), 17.68],
        [new Date("2014-04-01T08:11:00+00:00"), 10.97]
        //[...],

这很好用，但我喜欢按年份分隔值，例如每年一行来比较它们。如何设置没有年份的 x 轴 范围？

这是 result我喜欢实现，只有当我假装所有年份都一样时，这才有效。

Answer 1

我相信您想要一个离散的轴。然而，每个日期都是唯一的，因此结果是每个数据点都是轴上的一个离散点。所以诀窍是强制一个连续的轴并用格式修复。因此，您可以通过创建一个第一列为数字月份的 View 来完成此操作。通过将 0-11 个月转换为刻度值并强制每个刻度来修复格式。现在您可以保留原始值的日期。

顺便说一下，我几乎所有的图表都是这样做的:1) 使用数据表对行进行排序 2) 使用数据 View 对行和列进行筛选并生成派生值。 3) 使用选项来完成和/或抽象信息的呈现。

Working Example on jsFiddle

<div>
<div id='testchart'></div>
<script type="text/javascript">
function drawChart() {
    var data = new google.visualization.DataTable();
    data.addColumn('date', 'Date');
    data.addColumn('number', '2011');
    data.addColumn('number', '2012');
    data.addColumn('number', '2013');
    data.addColumn('number', '2014');

    data.addRows([
        [new Date("2011-02-01T15:18:21+00:00"), 21.77, null, null, null],
        [new Date("2011-03-01T15:18:59+00:00"), 20.96, null, null, null],
        [new Date("2011-04-01T15:19:22+00:00"), 15.75, null, null, null],
        [new Date("2011-05-01T15:19:44+00:00"), 6.92, null, null, null],
        [new Date("2011-06-01T08:12:00+00:00"), 4.46, null, null, null],
        [new Date("2011-07-06T07:54:00+00:00"), 2.54, null, null, null],
        [new Date("2011-08-01T15:30:21+00:00"), 2.96, null, null, null],
        [new Date("2011-09-01T15:30:35+00:00"), 2.94, null, null, null],
        [new Date("2011-10-01T15:30:58+00:00"), 3.3, null, null, null],
        [new Date("2011-11-01T15:31:37+00:00"), 10.72, null, null, null],
        [new Date("2011-12-01T07:54:15+00:00"), 17.04, null, null, null],
        [new Date("2012-01-01T10:29:00+00:00"), null, 20.43, null, null],
        [new Date("2012-02-01T08:03:00+00:00"), null, 22.51, null, null],
        [new Date("2012-03-01T08:07:00+00:00"), null, 26.75, null, null],
        [new Date("2012-04-01T12:58:04+00:00"), null, 13.09, null, null],
        [new Date("2012-05-01T12:58:59+00:00"), null, 13.52, null, null],
        [new Date("2012-06-01T08:09:00+00:00"), null, 4.71, null, null],
        [new Date("2012-07-01T13:00:06+00:00"), null, 3.92, null, null],
        [new Date("2012-08-01T08:02:00+00:00"), null, 2.85, null, null],
        [new Date("2012-09-01T09:52:18+00:00"), null, 3.05, null, null],
        [new Date("2012-10-01T17:13:00+00:00"), null, 4.2, null, null],
        [new Date("2012-11-01T10:03:00+00:00"), null, 10.79, null, null],
        [new Date("2012-12-01T10:52:00+00:00"), null, 16.68, null, null],
        [new Date("2013-01-02T16:16:00+00:00"), null, null, 20.7, null],
        [new Date("2013-02-03T13:51:00+00:00"), null, null, 24.41, null],
        [new Date("2013-03-01T08:06:00+00:00"), null, null, 25.44, null],
        [new Date("2013-04-01T09:58:00+00:00"), null, null, 23.15, null],
        [new Date("2013-05-01T20:26:00+00:00"), null, null, 12.13, null],
        [new Date("2013-06-01T13:19:00+00:00"), null, null, 6.77, null],
        [new Date("2013-07-01T18:09:00+00:00"), null, null, 4.26, null],
        [new Date("2013-08-23T14:32:00+00:00"), null, null, 2.67, null],
        [new Date("2013-09-01T09:41:00+00:00"), null, null, 3.25, null],
        [new Date("2013-10-01T12:42:14+00:00"), null, null, 5.2, null],
        [new Date("2013-11-01T12:43:17+00:00"), null, null, 8.95, null],
        [new Date("2013-12-01T12:43:38+00:00"), null, null, 17.02, null],
        [new Date("2014-01-01T10:19:00+00:00"), null, null, null, 16.24],
        [new Date("2014-02-01T10:16:00+00:00"), null, null, null, 19.13],
        [new Date("2014-03-01T08:05:00+00:00"), null, null, null, 17.68],
        [new Date("2014-04-01T08:11:00+00:00"), null, null, null, 10.97],
        [new Date("2014-05-01T09:06:00+00:00"), null, null, null, 6.57],
        [new Date("2014-07-01T07:57:00+00:00"), null, null, null, 4.25],
        [new Date("2014-08-03T11:26:00+00:00"), null, null, null, 2.14],
        [new Date("2014-09-02T08:04:00+00:00"), null, null, null, 2.95],
        [new Date("2014-10-01T07:18:00+00:00"), null, null, null, 3.75]
     ]);

    var dView = new google.visualization.DataView(data);
    dView.setColumns([
                        {calc:getmon, type:'number', label:"Month"}
                         ,1
                         ,2
                         ,3
                         ,4]);
    function getmon(dataTable, rowNum){
        var rd = dataTable.getValue(rowNum, 0);
        var rm = rd.getMonth();
        return {v:rm};
    }

    var options = {
            hAxis: {
            title: 'Month'
            ,showTextEvery: 1
            ,ticks: [{v:0, f:'Jan'}, {v:1, f:'Feb'}, {v:2, f:'Mar'}, {v:3, f:'Apr'}, {v:4, f:'May'}, {v:5, f:'Jun'}, {v:6, f:'Jul'}, {v:7, f:'Aug'}, {v:8, f:'Sep'}, {v:9, f:'Oct'}, {v:10, f:'Nov'}, {v:11, f:'Dec'}]
            }
}

    var chart = new google.visualization.LineChart(document.getElementById('testchart'));
    chart.draw(dView, options);
}
drawChart();
</script>