Question

我正在使用D3.js创建一个简单的折线图。

<div>
    <h6>Price Over Time</h6>
    <div id="priceOverTimeChart"></div>
</div>

// Set the dimensions of the canvas / graph
    var margin = {top: 30, right: 20, bottom: 30, left: 50},
        width = 800 - margin.left - margin.right,
        height = 270 - margin.top - margin.bottom;

    // Parse the date / time
    var parseDate = d3.time.format("%d-%b-%y").parse;

    // Set the ranges
    var x = d3.time.scale().range([0, width]);
    var y = d3.scale.linear().range([height, 0]);

    // Define the axes
    var xAxis = d3.svg.axis().scale(x)
        .orient("bottom").ticks(10);

    var yAxis = d3.svg.axis().scale(y)
        .orient("left").ticks(10);

    // Define the line
    var valueline = d3.svg.line()
        .x(function(d) { return x(d.date); })
        .y(function(d) { return y(d.close); });

    // Adds the svg canvas
    var svg = d3.select("#priceOverTimeChart")
        .append("svg")
            .attr("width", width + margin.left + margin.right)
            .attr("height", height + margin.top + margin.bottom)
        .append("g")
            .attr("transform", 
                  "translate(" + margin.left + "," + margin.top + ")");

    // Get the data
    d3.csv("data.csv", function(error, data) {
    data.forEach(function(d) {
        d.date = parseDate(d.date);
        d.close = +d.close;
    });

    // Scale the range of the data
    x.domain(d3.extent(data, function(d) { return d.date; }));
    y.domain([0, d3.max(data, function(d) { return d.close; })]);

    // Add the valueline path.
    svg.append("path")
        .attr("class", "line")
        .attr("d", valueline(data));

    // Add the X Axis
    svg.append("g")
        .attr("class", "x axis")
        .attr("transform", "translate(0," + height + ")")
        .call(xAxis);

    // Add the Y Axis
    svg.append("g")
        .attr("class", "y axis")
        .call(yAxis);


    });

折线图的数据使用以下数据格式：

26-Apr-12,0.048
25-Apr-12,0.048
24-Apr-12,0.048

我想为每条记录添加一个可选字符串，如下所示：

26-Apr-12,0.048, "product 1 launch",
25-Apr-12,0.048, "product 2",
24-Apr-12,0.048, "product 3"
26-Apr-12,0.048, null
25-Apr-12,0.048, null
24-Apr-12,0.048, null

图表看起来像这样，上面有标签：

Graph with optional labels

我怎样才能做到这一点？提前谢谢！

Answer 1

将文本附加到相应的x，y位置就可以了。

请参阅此工作JS Fiddle

svg.append("g").selectAll("text")
.data(data)
.enter()
.append("text")
.attr("x", function(d) { return x(d.date) - paddingForText })
.attr("y", function(d) { return y(d.close) + paddingForText })
.attr("fill", "red")
.text(function(d) { return d.notes });

将标签添加到d3折线图

1 个答案: