Philippe Rivière

I feel that Plot's stack transform is the correct answer now, but we need to design the API if we want to port it back to D3.

This package follows the convention in [d3-geo](https://github.com/d3/d3-geo), TopoJSON and ESRI shapefiles, which is (unfortunately) the opposite convention of GeoJSON’s [RFC 7946](https://tools.ietf.org/html/rfc7946#section-3.1.6).

Would be nice to have "properties" as a default channel, maybe—though this is an object, so we'd need a specific formatter too (?).

This looks like it would be a mix of curveStep and [curveCardinal](https://github.com/d3/d3-shape#curveCardinal)? I'm afraid you'll probably have to write your own [custom curve](https://github.com/d3/d3-shape#custom-curves).

We just merged the changes in d3-geo-projection. ``` geoproject --require d3=d3-composite-projections --precision 3 \ 'd3.geoConicConformalPortugal().translate([0,0]).scale(1)' [file] ```

See https://github.com/d3/d3-array/issues/90 and https://github.com/d3/d3-array/pull/150 — although in the case of dates it's hard to call that linspace, since days/weeks/months don't always have the same duration.

Here’s an example of grouped tips: not as complete as what you're suggesting, but I'm using Plot to generate it so it's easy to expand with marks and transforms. https://observablehq.com/@recifs/plot-grouped-tips

If the **href** channel exists, the tip should open the page (maybe with a second click on a link icon?)

About the "collection of dots" there is also the curvePoints proposal https://github.com/d3/d3-shape/issues/154

In interpolatorBarycentric we might want to interpolate only the inside of triangles where the longest edge is small enough.