D3.js d3-Fetch API

D3.js is a JavaScript library used for data visualization. It provides various modules that can be used to create a variety of charts and graphs. One of the modules is d3-fetch, which is used to load data from external sources. In this article, we will take a closer look at d3-fetch and how to use it to load data in D3.js.

Installation

To use d3-fetch, you first need to install D3.js. You can install it via NPM or download it directly from the D3.js website. Once you have installed D3.js, you can then use d3-fetch by including it in your project:

import { csv } from 'd3-fetch';

Loading Data

D3.js supports loading data from various sources such as CSV, TSV, JSON, and text files. The d3-fetch module provides various methods to load data from these sources.

csv

The csv method is used to load data from a comma-separated value (CSV) file. Here's an example:

csv('data.csv').then(function(data) {
  console.log(data);
});

This will load the data from data.csv and log it to the console.

tsv

The tsv method is similar to the csv method, but it is used to load data from a tab-separated value (TSV) file. Here's an example:

tsv('data.tsv').then(function(data) {
  console.log(data);
});

This will load the data from data.tsv and log it to the console.

json

The json method is used to load data from a JSON file. Here's an example:

json('data.json').then(function(data) {
  console.log(data);
});

This will load the data from data.json and log it to the console.

text

The text method is used to load data from a text file. Here's an example:

text('data.txt').then(function(data) {
  console.log(data);
});

This will load the data from data.txt and log it to the console.

Conclusion

The d3-fetch module provides a simple and powerful way to load data from external sources in D3.js. By understanding how to use the different methods, you can load data from a variety of sources and create beautiful visualizations with D3.js.