Philippe Rivière

A solution could be to pass the raw (parent) projection as an argument to the constructor, ie instead of `d3.geoWagnerEquallySpacedParallels().parentProjection(9)`, use `d3.geoWagnerEquallySpacedParallels(d3.geoAizmuthalEquidistantRaw)` (with a default value)?

OK I'll give it a try. I see that the code is available on your blog.

Confirmed. And it reminds me that the forward projection is wrong too (#178).

Related issue: when the connection between lobes is not made on the Equator, the map is wrong. The following video demonstrates an (exaggerated) view of the problem: the connections between...

I believe(d) this is considered "degenerate" in GeoJSON (but I admit I haven't been able to find a source). However there is necessarily a discontinuity: if you allow that coordinate...

(I've updated the reference image because the previous one had somehow disappeared.)

geoRectangularPolyconicRaw with no phi0 returns NaNs because geoRectangularPolyconicRaw is a function (of phi0) that returns a raw projection. So that's expected. The second part of your comment seems indeed to...

I just commited a change that addresses the issue. It's not complete (no inverse, no tests…), but it's a start :) You can test the build at https://observablehq.com/d/bde6f23d798d4f72 (it uses...

I'm sending you a suggestion with geoClipPolygon. It's not perfect because it clips up to the north pole even when that is not necessary, but it should be a good...

I've computed the inverse projections for sinucyli (suggestion at https://observablehq.com/d/59c257e99766c363).