This week in general, helped me realize how D3 iterates internally over the elements it creates. This was a doubt I needed to clarify last week. It also helped me realize general D3 semantics and selection patterns. I think I'm starting to "get the flow" of D3.
I'm having a hard time getting the bl.ocks.org
preview to render the page
correctly. The page renders correctly when observed outside the preview
using the raw address.
I think this might be related to separating the tutorials into separate
JavaScript files for organization, but I haven't confirmed this.
Modified http://d3js.org/d3.v3.min.js to a secure url
https://d3js.org/d3.v3.min.js