WikiAtlas ramp (beta)

This gist is a starting point to code a function buiding wikiatlas keys. It also gather helpful resources to learn and code further. Collaborative and versionned coding, fork, can be done on Codio.

We dream of…

Ideally, the function should take as input :

• the range [zmin, zmax] (?),
• an array for positives values [0, 50 200, 500, <zmax>],
• an array for negative values [<zmin>, -200, -100, -50, 0]

to then build a set of keys which manage both positive and negative altitudes,

Current code

Two different approches are implemented. One use a threshold scale, in the style of Ford Fessenden’s map of police stops involving force. A linear scale is used to set the x-position of each colored rectangle in the key. There is one rectangle per color in the threshold scale’s range, and one tick per value in the threshold scale’s domain. The linear scale’s domain sets the implied extent of the key, here spanning 0 to 100%. Explore D3’s ordinal scales may be productive.

Tutorial

• Let’s Make a Bar Chart I (code) - build HTML table.
• Let’s Make a Bar Chart II (code) - build SVG table from json, horizontal bars.
• Let’s Make a Bar Chart III (code) - build SVG table fron json, vertical bars with .domain(), .range(), .ticks().
• Margin Convention

Official

• d3.tsv - load and parse data
• d3.format - format percentages
• d3.scale.ordinal - x-position encoding
• d3.scale.linear - y-position encoding
• d3.max - compute domains
• d3.svg.axis - display axes and .ticks()

License

Public domain.