amCharts 中项目符号（箭头）的旋转

Question

我有一个图表显示了选定国家的两个时间点的变量演变。

箭头代表时间 2 中的水平。当值在时间 1 和时间 2 之间减小时（在我的示例中为意大利和德国），我希望箭头向下（旋转 180°）。相反，当值在时间 1 和时间 2 之间增加时，箭头应该向上（在我的示例中为瑞士、法国和西班牙）。

有谁知道我可以在我的 amCharts 中添加一段代码来自动旋转箭头？

我有一个带有我的数据和图形的 CodePen：https ://codepen.io/European-DataLab/pen/qBdyzap

我的代码是：

// Create chart instance

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

// Add data

chart.data = [

  {"Country":"Switzerland","time2":878,"time1":270},

 {"Country":"France","time2":1861,"time1":1237},

 {"Country":"Spain","time2":3431,"time1":1987.6667},

 {"Country":"Italy","time2":322,"time1":3911},

 {"Country":"Germany","time2":940,"time1":1120}];

// Create axis X

var categoryAxis = chart.xAxes.push(new am4charts.CategoryAxis());

categoryAxis.dataFields.category = "Country";

categoryAxis.renderer.grid.template.location = 0;

categoryAxis.renderer.minGridDistance = 1;

categoryAxis.renderer.labels.template.rotation = -45;

categoryAxis.renderer.labels.template.verticalCenter = "top";

categoryAxis.renderer.labels.template.horizontalCenter = "right";

categoryAxis.renderer.grid.template.disabled = true;

// Create axis Y

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

// Series for linking dot and arrow

var series = chart.series.push(new am4charts.ColumnSeries());

series.dataFields.categoryX = "Country";

series.dataFields.openValueY = "time1";

series.dataFields.valueY = "time2";

series.sequencedInterpolation = true;

series.fillOpacity = 0;

series.strokeOpacity = 1;

series.columns.template.stroke = am4core.color("#000000")

series.columns.template.width = 0.01;

series.tooltip.pointerOrientation = "horizontal";

//Series for Time 2

var dot1_1 = chart.series.push(new am4charts.LineSeries());

dot1_1.dataFields.valueY = "time2";

dot1_1.dataFields.categoryX = "Country";

dot1_1.strokeWidth = 0;

dot1_1.name = "Time 2";

Answer 1

这应该做的工作：arrow.adapter.add("rotation", function(rotation, target){&nbsp; if(target.dataItem.dataContext.time1 < target.dataItem.dataContext.time2){&nbsp; &nbsp; return 0&nbsp; }&nbsp; else{&nbsp; &nbsp; return 180&nbsp; }})