Node.js d3 package

The d3 package has data access functionality. In this case, we will read from a tab-separated file and compute an average. Note the use of the underscore variable name for lodash. Variable names starting with an underscore are assumed to be private. However, in this case, it is just a play on the name of the package we are using, which is lodash, or underscore. lodash is also a widely used a utility package.

For this script to execute, I had to do the following:

• Install d3
• Install lodash
• Install isomorphic-fetch (npm install --save isomorphic-fetch es6-promise)
• Import isomorphic-fetch

The script we will use is as follows:

var fs = require("fs");
var d3 = require("d3");
var _ = require("lodash");
var _ = require("isomorphic-fetch");

//read and parse the animals file
console.log("Animal\tWeight");
d3.csv("http://www.dantoomeysoftware.com/data/animals.csv", function(data) {
    console.log(data.name + '\t' + data.avg_weight);
});

This assumes that we have previously loaded the fs...