d3.js - d3js - 类型错误 : string is undefined

Question

我不明白这个错误:

TypeError: string is undefined function d3_time_parse(date, template, string, j) { var c, p, i = 0, n = template.length, m = string.length; ...

这是我的代码:

var margin = {top: 20, right: 80, bottom: 30, left: 50},
宽度 = 960 - margin.left - margin.right，
高度 = 500 - margin.top - margin.bottom;

var parseDate = d3.time.format("%Y%m%d").parse;

var x = d3.time.scale()
.range([0, 宽度]);

var y = d3.scale.linear()
.range([高度, 0]);

var 颜色 = d3.scale.category10();

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

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

var line = d3.svg.line()
.interpolate("基础")
.x(function(d) { return x(d.date); })
.y(function(d) { return y(d.index); });

var svg = d3.select("body").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 + ")");

d3.csv("data.csv", function(error, data) {
color.domain(d3.keys(data[0]).filter(function(key) { return key !== "date"; }));

数据.forEach(函数(d){
d.date = parseDate(d.date);
});

var 索引 = color.domain().map(function(name) {
返回 {
姓名:姓名，
值: data.map(function(d) {
返回{日期:d.date，索引:+d[名称]}；
})
};
});

x.domain(d3.extent(data, function(d) { return d.date; }));

y.domain([
d3.min(indexes, function(c) { return d3.min(c.values, function(v) { return v.index; }); }),
d3.max(indexes, function(c) { return d3.max(c.values, function(v) { return v.index; }); })
]);

svg.append("g")
.attr("class", "x 轴")
.attr("transform", "translate(0,"+ height + ")")
.call(xAxis);

svg.append("g")
.attr("class", "y 轴")
.call(yAxis)
.append("文本")
.attr(“变换”，“旋转(-90)”)
.attr("y", 6)
.attr("dy", ".71em")
.style("文本 anchor ", "结束")
.text("变化(%)");

var index = svg.selectAll(".index")
.data(索引)
.enter().append("g")
.attr("class", "index");

index.append("路径")
.attr("class", "line")
.attr("d", function(d) { return line(d.values); })
.style("stroke", function(d) { return color(d.name); });

index.append("文本")
.datum(function(d) { return {name: d.name, value: d.values[d.values.length - 1]}; })
.attr("transform", function(d) { return "translate("+ x(d.value.date) + ","+ y(d.value.index) + ")"; })
.attr("x", 3)
.attr("dy", ".35em")
.text(function(d) { return d.name; });
});

我的 csv 文件如下所示:

日期，DAX，CAC40，富时，纳斯达克，其他
20060407,-0.000712859,-0.009013212,0.010819606,0.009846526,0.003082604
20060413,-0.007765968,-0.024263398,0.011238971,0.004128621,0.005952774
20060421,0.02261859,0.00330204,0.028734861,0.001688981,0.003459211
20060428,0.007170521,-0.007531405,0.010534438,-0.002416181,0.004012361
...

有人可以帮我吗？
谢谢
串串

Answer 1

Date,DAX,CAC40,FTSE,NASDAQ,Other

JavaScript 变量名区分大小写，因此在解析带有上述标题的 CSV 文件时，您需要引用具有以下内容的字段:

d.Date // note the uppercase D
d.DAX // note all uppercase

这是来自 d3 wiki https://github.com/mbostock/d3/wiki/CSV#wiki-parse 的示例

Year,Make,Model,Length

1997,Ford,E350,2.34

2000,Mercury,Cougar,2.38

当使用 d3 的 CSV 解析器解析时，结果数据将由以下数组表示:

[
  {"Year": "1997", "Make": "Ford", "Model": "E350", "Length": "2.34"},
  {"Year": "2000", "Make": "Mercury", "Model": "Cougar", "Length": "2.38"}
]

请注意大写对象键。要访问第一个条目的年份，在 data[0].Year 中使用大写 Y 的“Year”将是必要的。

因此在您的 forEach你需要的功能:

data.forEach(function (d) {
    d.Date = parseDate(d.Date);
});

......后来:

return {date: d.Date, index: +d[name]};