javascript - amcharts 4 : Removing side padding on graphic starting point

Question

我有一个图表，它不是从 0 开始的。

这是我的图表和样本数据

am4core.useTheme(am4themes_animated);
var chart = am4core.create("chartdiv", am4charts.XYChart);

chart.dataSource.url = "https://api.myjson.com/bins/109xmw";
chart.dataSource.events.on("parseended", function(ev) {
    var data = ev.target.data;
    data.sort(function(lhs, rhs) {
        return lhs.time - rhs.time;
    });
    data.forEach(function(item) {
        item.time *= 1000;
    });
});

chart.numberFormatter.numberFormat = "#.0b";
chart.dateFormatter.inputDateFormat = "x";
var dateAxis = chart.xAxes.push(new am4charts.DateAxis());

dateAxis.dateFormats.setKey("minute", "d MMM, \nHH:mm");
dateAxis.periodChangeDateFormats.setKey("minute", "d MMM, \nHH:mm");

var valueAxis = chart.yAxes.push(new am4charts.ValueAxis());
valueAxis.tooltip.disabled = true;

var series = chart.series.push(new am4charts.LineSeries());
series.dataFields.dateX = "time";
series.name = "Traffic out";
series.dataFields.valueY = "outDiffFormatted";
series.tooltipHTML = "<span style='font-size:14px; color:#000000;'><b>{valueY.value}/s</b></span>";
series.tooltipText = "[#000]{valueY.value}[/]";
series.tooltip.background.fill = am4core.color("#FFF");
series.tooltip.getStrokeFromObject = true;
series.tooltip.background.strokeWidth = 3;
series.tooltip.getFillFromObject = false;
series.fillOpacity = 0.6;
series.strokeWidth = 2;
series.stacked = false;

var series2 = chart.series.push(new am4charts.LineSeries());
series2.dataFields.dateX = "time";
series2.name = "Traffic in";
series2.dataFields.valueY = "inDiffFormatted";
series2.tooltipHTML = "<span style='font-size:14px; color:#000000;'><b>{valueY.value}/s</b></span>";
series2.tooltipText = "[#000]{valueY.value}[/]";
series2.tooltip.background.fill = am4core.color("#FFF");
series2.tooltip.getFillFromObject = false;
series2.tooltip.getStrokeFromObject = true;
series2.tooltip.background.strokeWidth = 3;
series2.sequencedInterpolation = true;
series2.fillOpacity = 0.5;
series2.stacked = false;
series2.strokeWidth = 2;

chart.cursor = new am4charts.XYCursor();
chart.cursor.xAxis = dateAxis;
chart.scrollbarX = new am4core.Scrollbar();

chart.legend = new am4charts.Legend();
chart.legend.position = "top";

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
}
#chartdiv {
    width: 100%;
    height: 500px;
}

<script src="https://www.amcharts.com/lib/4/core.js"></script>
<script src="https://www.amcharts.com/lib/4/charts.js"></script>
<script src="https://www.amcharts.com/lib/4/themes/animated.js"></script>
<div id="chartdiv"></div>

我不明白为什么我有这个空白区域。

Answer 1

设置dateAxis.startLocation = 0.5;和dateAxis.endLocation = 0.5;，表示显示前半部分和尾半部分，使得系列向右延伸到绘图区域的边缘。

更多相关信息:https://www.amcharts.com/docs/v4/concepts/axes/positioning-axis-elements/

am4core.useTheme(am4themes_animated);
var chart = am4core.create("chartdiv", am4charts.XYChart);

chart.dataSource.url = "https://api.myjson.com/bins/109xmw";
chart.dataSource.events.on("parseended", function(ev) {
    var data = ev.target.data;
    data.sort(function(lhs, rhs) {
        return lhs.time - rhs.time;
    });
    data.forEach(function(item) {
        item.time *= 1000;
    });
});

chart.numberFormatter.numberFormat = "#.0b";
chart.dateFormatter.inputDateFormat = "x";
var dateAxis = chart.xAxes.push(new am4charts.DateAxis());

dateAxis.dateFormats.setKey("minute", "d MMM, \nHH:mm");
dateAxis.periodChangeDateFormats.setKey("minute", "d MMM, \nHH:mm");
dateAxis.startLocation = 0.5;
dateAxis.endLocation = 0.5;

var valueAxis = chart.yAxes.push(new am4charts.ValueAxis());
valueAxis.tooltip.disabled = true;

var series = chart.series.push(new am4charts.LineSeries());
series.dataFields.dateX = "time";
series.name = "Traffic out";
series.dataFields.valueY = "outDiffFormatted";
series.tooltipHTML = "<span style='font-size:14px; color:#000000;'><b>{valueY.value}/s</b></span>";
series.tooltipText = "[#000]{valueY.value}[/]";
series.tooltip.background.fill = am4core.color("#FFF");
series.tooltip.getStrokeFromObject = true;
series.tooltip.background.strokeWidth = 3;
series.tooltip.getFillFromObject = false;
series.fillOpacity = 0.6;
series.strokeWidth = 2;
series.stacked = false;

var series2 = chart.series.push(new am4charts.LineSeries());
series2.dataFields.dateX = "time";
series2.name = "Traffic in";
series2.dataFields.valueY = "inDiffFormatted";
series2.tooltipHTML = "<span style='font-size:14px; color:#000000;'><b>{valueY.value}/s</b></span>";
series2.tooltipText = "[#000]{valueY.value}[/]";
series2.tooltip.background.fill = am4core.color("#FFF");
series2.tooltip.getFillFromObject = false;
series2.tooltip.getStrokeFromObject = true;
series2.tooltip.background.strokeWidth = 3;
series2.sequencedInterpolation = true;
series2.fillOpacity = 0.5;
series2.stacked = false;
series2.strokeWidth = 2;

chart.cursor = new am4charts.XYCursor();
chart.cursor.xAxis = dateAxis;
chart.scrollbarX = new am4core.Scrollbar();

chart.legend = new am4charts.Legend();
chart.legend.position = "top";

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
}
#chartdiv {
    width: 100%;
    height: 320px;
}

<script src="https://www.amcharts.com/lib/4/core.js"></script>
<script src="https://www.amcharts.com/lib/4/charts.js"></script>
<script src="https://www.amcharts.com/lib/4/themes/animated.js"></script>
<div id="chartdiv"></div>