试图建立一个折线图(多行)。初始数据是一个对象数组,例如:
[{
2010: 8236.082,
countryName: "Afghanistan"
}]
每行都需要一个x / y对[[x,y],[x,y]]
的数组。我的x
和y
是year
和amount
的排放量。这意味着我必须重组数据使其看起来像这样:
[
{
country: "Afganistan",
emissions: [
{ year: 2019, amount: 8236.082 }
]
}
]
数据整理之后,我陷入了路径d = MNaN,NaNLNaN,NaN的问题。我在这里做什么错了?
//Define full width, full height and margins
let fullWidth = 600;
let fullHeight = 700;
let margin = {
top: 20,
left: 70,
bottom: 100,
right: 10
}
//Define line chart with and height
let width = fullWidth - margin.left - margin.right;
let height = fullHeight - margin.top - margin.bottom;
//Define x and y scale range
let xScale = d3.scaleLinear()
.range([0, width])
let yScale = d3.scaleLinear()
.range([0, height])
//Draw svg
let svg = d3.select("body")
.attr("width", fullWidth)
.attr("height", fullHeight)
.append("svg")
.append("g")
d3.json("https://api.myjson.com/bins/izmg6").then(data => {
console.log(data);
//Structure data so should be an array of arrays etc [[x,y], [x,y], [x,y]]
let years = d3.keys(data[0]).slice(0, 50);
console.log(years);
let dataset = [];
data.forEach((d, i) => {
let myEmissions = [];
years.forEach(y => {
if (d[y]) {
myEmissions.push({
year: y,
amount: d[y]
})
}
})
dataset.push({
country: d.countryName,
emissions: myEmissions
});
})
console.log(dataset);
//Define x and y domain
xScale
.domain(d3.extent(years))
yScale
.domain([d3.max(dataset, d =>
d3.max(d.emissions, d =>
+d.amount)), 0])
//Generate line
let line = d3.line()
.x(d => {
xScale(d.year);
})
.y(d => {
yScale(d.amount);
});
let groups = d3.selectAll("g")
.data(dataset)
.enter()
.append("g")
groups.append("title")
.text(d => d.country)
groups.selectAll("path")
.data(d => [d.emissions])
.enter()
.append("path")
.attr("d", line)
.attr("class", line)
}).catch(error => console.log(error))
答案 0 :(得分:-1)
NaN的主要问题是
let line = d3.line()
.x(d => xScale(d.year) )
.y(d => yScale(d.amount) );
但这不是图表的唯一问题。