Javascript/Maps

Planning out some simple map visualizations using Leaflet, build on those.

Also see Census Data and Tax Migration Data

Why maps?

The main point of these map visualizations is to learn Leaflet, D3, and Javascript. The advantages of using maps:

• no lack of interesting data sets
• data sets get very large very fast, so provides motivation for learning to bundle data, deal with "promises" etc.
• maps are mainly interesting when linked to another component, so focus on learning to link pieces

Components

Building maps in Javscript requires a few moving parts.

First, the Javascript dependency manager. Unconventionally, I'm staying as far away from Javascript package managers as possible. No Bower, Grunt, Backbone, Gulp, Node, or whatever other stupid framework is most popular these days. Just use Javascript.

Second, the static page content generator. Pages are managed using Pelican. The setup is basically to create a separate folder with all files related to the map application, and keep everything as minimal and standalone as possible. Creating a map should not require modifying the pelican theme.

Third, the Javascript/css/html files for the map itself. These are managed by Pelican and sit together in a single directory.

Phases

Phase 1: Map Only

Simple map

• leaflet with mapbox tiles
• pelican javascript css files workflow
• on click, popup with latitude longitude

Final link: https://git.charlesreid1.com/d3/maps/src/master/map-mouse

Active map

• leaflet
• geojson data
• on click, popup with shape info

Final link: https://git.charlesreid1.com/d3/maps/src/master/map-shapes

Cards map

• leaflet
• geojson data
• on click, modify another element

Final link: https://git.charlesreid1.com/d3/maps/src/master/map-cards

Hover map

• leaflet
• geojson data
• on hover, change color
• on click change color

Final link: https://git.charlesreid1.com/d3/maps/src/master/map-hover

Phase 2: Map and C3

C3 is good for very simple, no-nonsense line/area/bar/donut charts. C3 is a shut-up-and-be-happy-with-what-you-got sort of setup - near zero customization, everything through the API, no way to connect components. Either you're happy with the C3 chart, or you find a D3 chart that does exactly what you want and have at it because the guts are right there.

Simple map and C3 chart:

• leaflet
• c3
• chart data is static
• only chart title is linked to county maps
• NOTE: This illustrates how stupidly difficult it is to get C3 to interact with anyone else on the page.

Code

Code for each map is being staged here: https://git.charlesreid1.com/d3/maps

Final deployed maps are checked into charlesreid1.com repo here: https://git.charlesreid1.com/charlesreid1/charlesreid1.com

Specifically, example map is here: https://git.charlesreid1.com/charlesreid1/charlesreid1.com/src/charlesreid1-src/pelican/examplemap

Final version of example map is here: http://charlesreid1.com/examplemap/

Lessons

I always try to do a post-mortem on why D3 and Javascript make life so difficult when building visualizations.

Those are here: D3