datasets

Utilities to facilitate working with vega/vega-datasets

Vega datasets are a collection of datasets used in Vega and in Vega-Lite examples.

The data lives at https://github.com/vega/vega-datasets and https://cdn.jsdelivr.net/npm/vega-datasets

For those of you familiar with Pandas, please consider looking at danfo.js and DataFrame.js

Example

datasets.list(); //-- prints the list of the datasets supported
myDataset = datasets.fetch('cars.json');

Methods

(static) fetch(library) → {Promise.<any>}

See:

Fetches a specific dataset from within the list available from vega-datasets

Example:

Using utils.datasets.list() we can see the list of datasets

['barley.json', 'cars.json', ...]

We can then fetch the dataset using that key, and accepting the promise. (Note that this option does not pause execution before running the next cell)

datasets.fetch('cars.json').then(results => cars = results);
[
  {
    Name: 'chevrolet chevelle malibu',
    Miles_per_Gallon: 18,
    Cylinders: 8,
    Displacement: 307,
    Horsepower: 130,
    Weight_in_lbs: 3504,
    Acceleration: 12,
    Year: '1970-01-01',
    Origin: 'USA'
  },
  ...
];

Note - the utils.ijs.await method can simplify this call, to support await.

utils.ijs.await(async ($$, console) => {
  gapMinder = await utils.datasets.load('gapminder.json');
});
Parameters:
Name Type Description
library string

one of the names of the libraries available from list
Returns:
  • results from the dataset
Type
Promise.<any>

(static) fetchJSON(targetAddress, options) → {Object}

Simple fetch call for JSON handling simple cases.

const response = await fetch(targetAddress, options);
if (!response.ok) throw new Error(`unexpected response ${response.statusText}`);
return response.json();
Example
utils.ijs.await(async ($$, console) => {
 worldJSON = await utils.datasets.fetchJSON('https://unpkg.com/world-atlas@1/world/110m.json');
 console.log(worldJSON.type); // Topology
});

// use worldJSON as global variable
Parameters:
Name Type Description
targetAddress String

Address of the file to load
options Object

options to pass to fetch
Returns:
  • parsed JSON of the response
Type
Object

(static) fetchText(targetAddress, options) → {Object}

Simple fetch call for Text handling simple cases.

const response = await fetch(targetAddress, options);
if (!response.ok) throw new Error(`unexpected response ${response.statusText}`);
return response.text();
Example
utils.ijs.await(async ($$, console) => {
    myText = await utils.datasets.fetchText('https://unpkg.com/qr-image@3.2.0/LICENSE');
    return myText;
});

// use myText as global variable
Parameters:
Name Type Description
targetAddress String

Address of the file to load
options Object

options to pass to fetch
Returns:
  • parsed JSON of the response
Type
Object

(static) list() → {Array.<String>}

Prints the lists of datasets available

Example
datasets.list();

// [
// 'annual-precip.json',
// 'anscombe.json',
// 'barley.json',
// 'budget.json',
// 'budgets.json',
// 'burtin.json',
// 'cars.json',
// 'countries.json',
// 'crimea.json',
// 'driving.json',
// ... ];
Returns:
  • list of dataset ids that can be fetched.
Type
Array.<String>

(static) polyfillFetch()

Polyfill for 'global.fetch' if your nodejs instance does not have an implementation (and will only polyfill if so);

Once executed, global.fetch will have an implementation.

See the node-fetch library for more details