I am following some examples of d3.js to plot graphs. For reference here is the link.
Following is the code where I've used the LineChart function to build the plot. With Django as backend.
{% load static %}
<html>
<script src="https://d3js.org/d3.v6.js"></script>
<body>
<h1> Hello! </h1>
<div id="chart"></div>
</body>
<script>
// set the dimensions and margins of the graph
const margin = {top: 10, right: 30, bottom: 30, left: 60},
width = 460 - margin.left - margin.right,
height = 400 - margin.top - margin.bottom;
// append the svg object to the body of the page
const svg = d3.select("#chart")
.append("chart")
.attr("width", width margin.left margin.right)
.attr("height", height margin.top margin.bottom)
.append("g")
.attr("transform", `translate(${margin.left},${margin.top})`);
// Copyright 2021 Observable, Inc.
// Released under the ISC license.
// https://observablehq.com/@d3/line-chart
function LineChart(data, {
x = ([x]) => x, // given d in data, returns the (temporal) x-value
y = ([, y]) => y, // given d in data, returns the (quantitative) y-value
defined, // for gaps in data
curve = d3.curveLinear, // method of interpolation between points
marginTop = 20, // top margin, in pixels
marginRight = 30, // right margin, in pixels
marginBottom = 30, // bottom margin, in pixels
marginLeft = 40, // left margin, in pixels
width = 640, // outer width, in pixels
height = 400, // outer height, in pixels
xType = d3.scaleUtc, // the x-scale type
xDomain, // [xmin, xmax]
xRange = [marginLeft, width - marginRight], // [left, right]
yType = d3.scaleLinear, // the y-scale type
yDomain, // [ymin, ymax]
yRange = [height - marginBottom, marginTop], // [bottom, top]
yFormat, // a format specifier string for the y-axis
yLabel, // a label for the y-axis
color = "currentColor", // stroke color of line
strokeLinecap = "round", // stroke line cap of the line
strokeLinejoin = "round", // stroke line join of the line
strokeWidth = 1.5, // stroke width of line, in pixels
strokeOpacity = 1, // stroke opacity of line
} = {}) {
// Compute values.
const X = d3.map(data, x);
const Y = d3.map(data, y);
const I = d3.range(X.length);
if (defined === undefined) defined = (d, i) => !isNaN(X[i]) && !isNaN(Y[i]);
const D = d3.map(data, defined);
// Compute default domains.
if (xDomain === undefined) xDomain = d3.extent(X);
if (yDomain === undefined) yDomain = [0, d3.max(Y)];
// Construct scales and axes.
const xScale = xType(xDomain, xRange);
const yScale = yType(yDomain, yRange);
const xAxis = d3.axisBottom(xScale).ticks(width / 80).tickSizeOuter(0);
const yAxis = d3.axisLeft(yScale).ticks(height / 40, yFormat);
// Construct a line generator.
const line = d3.line()
.defined(i => D[i])
.curve(curve)
.x(i => xScale(X[i]))
.y(i => yScale(Y[i]));
const svg = d3.create("svg")
.attr("width", width)
.attr("height", height)
.attr("viewBox", [0, 0, width, height])
.attr("style", "max-width: 100%; height: auto; height: intrinsic;");
svg.append("g")
.attr("transform", `translate(0,${height - marginBottom})`)
.call(xAxis);
svg.append("g")
.attr("transform", `translate(${marginLeft},0)`)
.call(yAxis)
.call(g => g.select(".domain").remove())
.call(g => g.selectAll(".tick line").clone()
.attr("x2", width - marginLeft - marginRight)
.attr("stroke-opacity", 0.1))
.call(g => g.append("text")
.attr("x", -marginLeft)
.attr("y", 10)
.attr("fill", "currentColor")
.attr("text-anchor", "start")
.text(yLabel));
svg.append("path")
.attr("fill", "none")
.attr("stroke", color)
.attr("stroke-width", strokeWidth)
.attr("stroke-linecap", strokeLinecap)
.attr("stroke-linejoin", strokeLinejoin)
.attr("stroke-opacity", strokeOpacity)
.attr("d", line(I));
return svg.node();
};
var aapl = [
{
"Date": 1641168000000,
"Close": 182.01
},
{
"Date": 1641254400000,
"Close": 179.7
},
{
"Date": 1641168000000,
"Close": 174.92
},
];
var chart = LineChart(aapl, {
x: d => d.Date,
y: d => d.Close,
yLabel: "↑ Daily close ($)",
width: 400,
height: 500,
color: "steelblue"
})
</script>
</html>
I still learning javascript and specifically the d3.js library. I am unable to display the plot. What is wrong in the shared code and how can I fix it?
CodePudding user response：
There are 2 problems with your code. You are appending chart before it is created and also you need to use appendChild Method as you are returning node of the svg element.
d3 allows to append nodes created by d3.create by using appendChild. I have changed your code below to use appendChild to attach svg node to the chart div node.
// set the dimensions and margins of the graph
const margin = {
top: 10,
right: 30,
bottom: 30,
left: 60
},
width = 460 - margin.left - margin.right,
height = 400 - margin.top - margin.bottom;
// Copyright 2021 Observable, Inc.
// Released under the ISC license.
// https://observablehq.com/@d3/line-chart
function LineChart(data, {
x = ([x]) => x, // given d in data, returns the (temporal) x-value
y = ([, y]) => y, // given d in data, returns the (quantitative) y-value
defined, // for gaps in data
curve = d3.curveLinear, // method of interpolation between points
marginTop = 20, // top margin, in pixels
marginRight = 30, // right margin, in pixels
marginBottom = 30, // bottom margin, in pixels
marginLeft = 40, // left margin, in pixels
width = 640, // outer width, in pixels
height = 400, // outer height, in pixels
xType = d3.scaleUtc, // the x-scale type
xDomain, // [xmin, xmax]
xRange = [marginLeft, width - marginRight], // [left, right]
yType = d3.scaleLinear, // the y-scale type
yDomain, // [ymin, ymax]
yRange = [height - marginBottom, marginTop], // [bottom, top]
yFormat, // a format specifier string for the y-axis
yLabel, // a label for the y-axis
color = "currentColor", // stroke color of line
strokeLinecap = "round", // stroke line cap of the line
strokeLinejoin = "round", // stroke line join of the line
strokeWidth = 1.5, // stroke width of line, in pixels
strokeOpacity = 1, // stroke opacity of line
} = {}) {
// Compute values.
const X = d3.map(data, x);
const Y = d3.map(data, y);
const I = d3.range(X.length);
if (defined === undefined) defined = (d, i) => !isNaN(X[i]) && !isNaN(Y[i]);
const D = d3.map(data, defined);
// Compute default domains.
if (xDomain === undefined) xDomain = d3.extent(X);
if (yDomain === undefined) yDomain = [0, d3.max(Y)];
// Construct scales and axes.
const xScale = xType(xDomain, xRange);
const yScale = yType(yDomain, yRange);
const xAxis = d3.axisBottom(xScale).ticks(width / 80).tickSizeOuter(0);
const yAxis = d3.axisLeft(yScale).ticks(height / 40, yFormat);
// Construct a line generator.
const line = d3.line()
.defined(i => D[i])
.curve(curve)
.x(i => xScale(X[i]))
.y(i => yScale(Y[i]));
const svg = d3.create("svg")
.attr("width", width)
.attr("height", height)
.attr("viewBox", [0, 0, width, height])
.attr("style", "max-width: 100%; height: auto; height: intrinsic;");
svg.append("g")
.attr("transform", `translate(0,${height - marginBottom})`)
.call(xAxis);
svg.append("g")
.attr("transform", `translate(${marginLeft},0)`)
.call(yAxis)
.call(g => g.select(".domain").remove())
.call(g => g.selectAll(".tick line").clone()
.attr("x2", width - marginLeft - marginRight)
.attr("stroke-opacity", 0.1))
.call(g => g.append("text")
.attr("x", -marginLeft)
.attr("y", 10)
.attr("fill", "currentColor")
.attr("text-anchor", "start")
.text(yLabel));
svg.append("path")
.attr("fill", "none")
.attr("stroke", color)
.attr("stroke-width", strokeWidth)
.attr("stroke-linecap", strokeLinecap)
.attr("stroke-linejoin", strokeLinejoin)
.attr("stroke-opacity", strokeOpacity)
.attr("d", line(I));
return svg.node();
}
var aapl = [{
"Date": 1641168000000,
"Close": 182.01
},
{
"Date": 1641254400000,
"Close": 179.7
},
{
"Date": 1641168000000,
"Close": 174.92
},
];
var chart = LineChart(aapl, {
x: d => d.Date,
y: d => d.Close,
yLabel: "↑ Daily close ($)",
width: 400,
height: 500,
color: "steelblue"
})
// append the svg object to the body of the page
const svg = d3.select("#chart").node().appendChild(chart);<script src="https://d3js.org/d3.v6.js"></script>
<body>
<h1> Hello! </h1>
<div id="chart"></div>
</body>