javascript - 访问 D3 多线图表上工具提示中的数据

Question

这是我的数据。

var data = [
    {
        "label": "branch-1",
        "values": [
            { "day": "Monday", "value": 20},
            { "day": "Tuesday", "value": 18},
            { "day": "Wednesday", "value": 29},
            { "day": "Thursday", "value": 31},
            { "day": "Friday", "value": 37},
            { "day": "Saturday", "value": 25},
            { "day": "Sunday", "value": 19}
        ]
    },
    {
        "label": "branch-2",
        "values": [
            { "day": "Monday", "value": 32},
            { "day": "Tuesday", "value": 29},
            { "day": "Wednesday", "value": 37},
            { "day": "Thursday", "value": 41},
            { "day": "Friday", "value": 31},
            { "day": "Saturday", "value": 28},
            { "day": "Sunday", "value": 17}
        ]
    }
]

我试图将标签添加到工具提示中，但是收到错误“未定义”。我还需要在每行末尾添加标签。类似地，名字在 this例子。但我找不到如何实现这一目标。

我的代码的 fiddle 链接是 here .

Answer 1

要在工具提示中获取标签，您需要在各个数据点中包含标签名称:

修改数据处理 block 如下:

data.forEach(function (kv) {
    var labelName = kv.label;
    kv.values.forEach(function (d) {
        d.value = +d.value; 
        d.label = labelName;
    });
});

要添加标签，请添加以下部分:

city.append("text")
      .attr("transform", function(d) { var dayExt = d.values[d.values.length - 1].day; var valueExt = d.values[d.values.length - 1].value;  return "translate(" +  x(dayExt) + "," + y(valueExt) + ")"; })
      .attr("x", 3)
      .attr("dy", ".35em")
      .text(function(d) { return d.label });

请在这里找到完整的 fiddle :http://jsfiddle.net/prashant_11235/LY8zt/

您可以根据需要适当设置标签名称的样式。