Visualizing UFO data

We'll spend a good bit of time visualizing the data, and we'll use the same system that we have in the previous chapters: a bit of HTML, a splash of CSS, and a lot of JavaScript, which we'll generate from ClojureScript.

We've already taken care of the configuration for using ClojureScript in the project.clj file that I mentioned earlier. The rest of it involves a couple of more parts:

• The code to generate the JSON data for the graph. This will be in the src/ufo_data/analysis.clj file. We'll write this code first.

• An HTML page that loads the JavaScript libraries that we'll use—jQuery (https://jquery.org/) and D3 (http://d3js.org/)—and creates a div container in which to put the graph itself.

• The source code for the graph. This will include a namespace for utilities in src-cljs/ufo-data/utils.cljs and the main namespace at src-cljs/ufo-data/viz.cljs.

With these prerequisites in place, we can start creating the graph of the frequencies of the different shapes.

First, we need...