Support linestring

[akacarlyann]

Adds class for LinestringViz with geojson and vector data source support. Line color and width are data-driven styled. Addresses #4, #81.

Still working on:

• legend refinement
• default color/line width test (make sure consistent with latest CircleViz and ChoroplethViz)
• bugfix for match-type color on vector linestring example
• clean up example linestring-viz.ipynb

[akacarlyann]

@ryanbaumann Ready for you to take a first look.

Bug mentioned above is actually fixed with a refinement to the color_map function (when I wrote it I assumed match-type would entail non-numeric stops, given numeric color stops and color_function_type = 'match', color_map is interpolating rather than returning the default color). Fix would be adding an argument to color_map to override this behavior for 'match' color_function_type and numeric stops. I can open a separate PR for that -- thoughts?

[ryanbaumann]

New PR for the bug fix on color_map @akacarlyann 👍 .

This is amazing. Taking a look now.

[ryanbaumann]

Dropping an example here of what this looks like (Mount Diablo elevation contours styled by width and color based on elevation) from your example notebook @akacarlyann

[akacarlyann]

Perfect! I knew you'd have something in the wings for this.

[ryanbaumann]

@akacarlyann will target a PR review tomorrow

[ryanbaumann]

Just add the extra label style properties to match the other viz types @akacarlyann and all set!

[ryanbaumann]

Make text-color, halo-color, halo-width, and text-size adjustable to math other visuals labels. https://github.com/mapbox/mapboxgl-jupyter/blob/master/mapboxgl/templates/circle.html#L38

[ryanbaumann]

Likewise in the vector linestring layer - add style modifiers for text-color, text-size, halo-color, halo-width

[akacarlyann]

Thanks @ryanbaumann ! Added these in 3e9fac4. Looks like I'll need to update ChoroplethViz too in a separate issue.

[ryanbaumann]

Nice @akacarlyann! Add the new lable style property options to the Markdown Docs, then 🚢 ! So excited to get this one into python dev's hands.

[akacarlyann]

@ryanbaumann Added LinestringViz to viz.md in 9bf8311.