JS TutorialLesson #275

D3.js

> D3.js is a JavaScript library for manipulating HTML data.

D3.js is a JavaScript library for manipulating HTML data. > D3.js is easy to use.

How to Use D3.js?

To use D3.js in your web page, add a link to the library:

Example

Example Code

html

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This script selects the body element and appends a paragraph with the text "Hello World!":

Example

Example Code

javascript

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d3.select("body").append("p").text("Hello World!");

Scatter Plot

Example

Example Code

javascript

Try it Yourself

// Set Dimensions

const xSize = 500;

const ySize = 500;

const margin = 40;

const xMax = xSize - margin*2;

const yMax = ySize - margin*2;

// Create Random Points

const numPoints = 100;

const data = [];

for (let i = 0; i < numPoints; i++) {

  data.push([Math.random() * xMax, Math.random() * yMax]);

}

// Append SVG Object to the Page

const svg = d3.select("#myPlot")

  .append("svg")

  .append("g")

  .attr("transform","translate(" + margin + "," + margin + ")");

// X Axis

const x = d3.scaleLinear()

  .domain([0, 500])

  .range([0, xMax]);

svg.append("g")

  .attr("transform", "translate(0," + yMax + ")")

  .call(d3.axisBottom(x));

// Y Axis

const y = d3.scaleLinear()

  .domain([0, 500])

  .range([ yMax, 0]);

svg.append("g")

  .call(d3.axisLeft(y));

// Dots

svg.append('g')

  .selectAll("dot")

  .data(data).enter()

  .append("circle")

  .attr("cx", function (d) { return d[0] } )

  .attr("cy", function (d) { return d[1] } )

  .attr("r", 3)

  .style("fill", "Red");

Interactive Code Examples

Example 1

html

Try it Yourself

JavaScript syntax and algorithm demonstration.

<script src="//d3js.org/d3.v3.min.js"></script>

Example 2

javascript

Try it Yourself

JavaScript syntax and algorithm demonstration.

d3.select("body").append("p").text("Hello World!");

JS Example 3

javascript

Try it Yourself

JavaScript syntax and algorithm demonstration.

// Set Dimensions

const xSize = 500;

const ySize = 500;

const margin = 40;

const xMax = xSize - margin*2;

const yMax = ySize - margin*2;



// Create Random Points

const numPoints = 100;

const data = [];

for (let i = 0; i < numPoints; i++) {

  data.push([Math.random() * xMax, Math.random() * yMax]);

}



// Append SVG Object to the Page

const svg = d3.select("#myPlot")

  .append("svg")

  .append("g")

  .attr("transform","translate(" + margin + "," + margin + ")");



// X Axis

const x = d3.scaleLinear()

  .domain([0, 500])

  .range([0, xMax]);



svg.append("g")

  .attr("transform", "translate(0," + yMax + ")")

  .call(d3.axisBottom(x));



// Y Axis

const y = d3.scaleLinear()

  .domain([0, 500])

  .range([ yMax, 0]);



svg.append("g")

  .call(d3.axisLeft(y));



// Dots

svg.append('g')

  .selectAll("dot")

  .data(data).enter()

  .append("circle")

  .attr("cx", function (d) { return d[0] } )

  .attr("cy", function (d) { return d[1] } )

  .attr("r", 3)

  .style("fill", "Red");

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