javascript - 错误 : attribute y1: Expected length, "NaN"

Question

我正在尝试使用 d3 v3 显示箱线图，但我收到了与其他同类错误一起提到的错误:

Error: <line> attribute y2: Expected length, "NaN".

Error: <rect> attribute y: Expected length, "NaN".

完整错误信息:

Error: attribute y: Expected length, "NaN". o @ d3.v3.min.js:1 (anonymous) @ d3.v3.min.js:3 R @ d3.v3.min.js:1 da.each @ d3.v3.min.js:3 da.attr @ d3.v3.min.js:3 (anonymous) @ box.js:103 (anonymous) @ d3.v3.min.js:3 R @ d3.v3.min.js:1 da.each @ d3.v3.min.js:3 box @ box.js:19 da.call @ d3.v3.min.js:3 (anonymous) @ subject:262 (anonymous) @ d3.v3.min.js:1 t @ d3.v3.min.js:1 u @ d3.v3.min.js:1 load (async) St @ d3.v3.min.js:1 e @ d3.v3.min.js:3 (anonymous) @ subject:170

我从一个网站上得到了js代码，所以我只是改变了他们提到的参数......图表的js代码如下:

var labels = true; // show the text labels beside individual boxplots?
var margin = {
    top: 30,
    right: 50,
    bottom: 70,
    left: 50
};
var width = 800 - margin.left - margin.right;
var height = 400 - margin.top - margin.bottom;

var min = 1000,
    max = -1000;

// parse in the data    
d3.csv("../static/CSV/Chart_data/boxplot_year.csv?rnd='+(new Date).getTime()", function(error, csv) {
    // using an array of arrays with
    // data[n][2] 
    // where n = number of columns in the csv file 
    // data[i][0] = name of the ith column
    // data[i][1] = array of values of ith column

    var data = [];
    data[0] = [];
    data[1] = [];
    data[2] = [];
    data[3] = [];
    data[4] = [];
    data[5] = [];
    // add more rows if your csv file has more columns

    // add here the header of the csv file
    data[0][0] = "Y1";
    data[1][0] = "Y2";
    data[2][0] = "Y3";
    data[3][0] = "Y4";
    data[4][0] = "Y5";
    data[5][0] = "Y6";
    // add more rows if your csv file has more columns

    data[0][1] = [];
    data[1][1] = [];
    data[2][1] = [];
    data[3][1] = [];
    data[4][1] = [];
    data[5][1] = [];

    csv.forEach(function(x) {
        var v1 = Math.floor(x.Y1),
            v2 = Math.floor(x.Y2),
            v3 = Math.floor(x.Y3),
            v4 = Math.floor(x.Y4),
            v5 = Math.floor(x.Y5),
            v6 = Math.floor(x.Y6);
        // add more variables if your csv file has more columns

        var rowMax = Math.max(Math.max(v1, v2), Math.max(Math.max(v3, v4), Math.max(v5, v6)));
        var rowMin = Math.min(Math.min(v1, v2), Math.min(Math.min(v3, v4), Math.min(v5, v6)));

        data[0][1].push(v1);
        data[1][1].push(v2);
        data[2][1].push(v3);
        data[3][1].push(v4);
        data[4][1].push(v5);
        data[5][1].push(v6);
        // add more rows if your csv file has more columns

        if (rowMax > max) max = rowMax;
        if (rowMin < min) min = rowMin;
    });

    var chart = d3.box()
        .whiskers(iqr(1.5))
        .height(height)
        .domain([min, max])
        .showLabels(labels);

    var svg = d3.select("body").append("svg")
        .attr("width", width + margin.left + margin.right)
        .attr("height", height + margin.top + margin.bottom)
        .attr("class", "box")
        .append("g")
        .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

    // the x-axis
    var x = d3.scale.ordinal()
        .domain(data.map(function(d) {
            console.log(d);
            return d[0];
        }))
        .rangeRoundBands([0, width], 0.7, 0.3);

    var xAxis = d3.svg.axis()
        .scale(x)
        .orient("bottom");

    // the y-axis
    var y = d3.scale.linear()
        .domain([min, max])
        .range([height + margin.top, 0 + margin.top]);

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

    // draw the boxplots    
    svg.selectAll(".box")
        .data(data)
        .enter().append("g")
        .attr("transform", function(d) {
            return "translate(" + x(d[0]) + "," + margin.top + ")";
        })
        .call(chart.width(x.rangeBand()));


    // add a title
    svg.append("text")
        .attr("x", (width / 2))
        .attr("y", 0 + (margin.top / 2))
        .attr("text-anchor", "middle")
        .style("font-size", "18px")
        //.style("text-decoration", "underline")  
        .text("Grade through the years");

    // draw y axis
    svg.append("g")
        .attr("class", "y axis")
        .call(yAxis)
        .append("Grade") // and text1
        .attr("transform", "rotate(-90)")
        .attr("y", 6)
        .attr("dy", ".71em")
        .style("text-anchor", "end")
        .style("font-size", "16px")
        .text("Revenue in €");

    // draw x axis  
    svg.append("g")
        .attr("class", "x axis")
        .attr("transform", "translate(0," + (height + margin.top + 10) + ")")
        .call(xAxis)
        .append("Year") // text label for the x axis
        .attr("x", (width / 2))
        .attr("y", 10)
        .attr("dy", ".71em")
        .style("text-anchor", "middle")
        .style("font-size", "16px")
        .text("Quarter");
});

// Returns a function to compute the interquartile range.
function iqr(k) {
    return function(d, i) {
        var q1 = d.quartiles[0],
            q3 = d.quartiles[2],
            iqr = (q3 - q1) * k,
            i = -1,
            j = d.length;
        while (d[++i] < q1 - iqr);
        while (d[--j] > q3 + iqr);
        return [i, j];
    };
}

我的 csv 文件是:

Y1,Y2,Y3,Y4,Y5,Y6

3.8,5.7,0.0,6.8,8.2,6.8

5.0,1.5,5.0,0.0,6.1,9.0

4.0,5.6,5.5,4.1,5.5,5.1

5.4,6.7,5.1,5.0,9.0,6.8

5.5,5.3,8.0,8.6,6.1,7.7

8.0,1.7,4.6,6.1,7.6,5.9

6.3,7.3,6.8,8.3,6.0,0.0

5.0,5.1,6.6,7.8,5.4,3.5

5.6,3.7,7.0,5.1,7.1,2.7

8.5,6.0,1.8,7.7,2.5,8.0

6.4,9.8,5.8,7.0,6.8,8.7

6.7,7.5,5.0,6.3,0.0,7.4

有什么想法吗？提前致谢!

Answer 1

问题似乎在于将数据传递给箱线图:

// draw the boxplots    
svg.selectAll(".box")
    .data(data)
    .enter().append("g")
    .attr("transform", function(d) {
        return "translate(" + x(d[0]) + "," + margin.top + ")";
    })
    .call(chart.width(x.rangeBand()));

您的 data 数组是 2 元素子数组的数组，其中每个子数组由一个列标签和另一个子数组中的一列数据组成。例如，data[2][0] 是 "Y3" 但 data[2][1] 是对应年份的数据 Y3([0, 5, 5, 5, 8, ... ])。

D3 对此感到困惑:它尝试将 2 元素数组中的两个值都转换为数字，当然将列子数组转换为单个数字失败并以 NaN 结尾.

您需要做的是仅将列子数组的数组传递给 .data()。然后，对于transform属性，将对应的label传入x函数。 transform 中调用的函数通过索引和数据列:我们使用此索引来获取相应的标签。

因此，请尝试将上面的行替换为以下行:

// draw the boxplots    
svg.selectAll(".box")
    .data(data.map(function (d) { return d[1]; }))
    .enter().append("g")
    .attr("transform", function(d, i) {
        return "translate(" + x(data[i][0]) + "," + margin.top + ")";
    })
    .call(chart.width(x.rangeBand()));