为什么 amChart 将数据居中?

Why does amChart center the line with few data?

看看这个演示:http://jsfiddle.net/2313ffbf/

数据生成者:

// generate some random data, quite different range
function generateChartData() {
    var chartData = [];
    // current date
    var firstDate = new Date();
    // now set 500 minutes back
    firstDate.setMinutes(firstDate.getDate() - 1000);

    // and generate data items
    var visits = 30; // <--- change this to 500
    for (var i = 0; i < visits; i++) {
        var newDate = new Date(firstDate);
        // each time we add one minute
        newDate.setMinutes(newDate.getMinutes() + i);
        // some random number
        visits += Math.round((Math.random()<0.5?1:-1)*Math.random()*10);
        // add data item to the array
        chartData.push({
            date: newDate,
            visits: visits
        });
    }
    return chartData;
}

如果你 运行 它你可以看到折线图不是在边缘而是居中。

如果您将 var visits = 30; 更改为 500 之类的值,则该线会触及页边距。

我怎样才能用很少的数据得到它?

尝试在您的图表配置中更加具体。因此,而不是 mm(分钟)写 fff(毫秒):

var chart = AmCharts.makeChart("chartdiv", {
  ...
  "categoryAxis": {
    "minPeriod": "fff",
    "parseDates": true
  },
  ...
});

了解更多 here