Experimental projections

[Atarimaster]

Excellent work. Love it!

I agree – and I also like your latest results.
Nice to see that my questions triggered the presentation of a bunch of great ideas!

[brsr]

I read your paper a while ago; sorry that I did not get back to you about it. It’s a good paper. Do you intend to publish?

I had a busy spring, but I'm finally getting back around to submitting it.

I might implement this in Geocart if you don’t mind. It probably won’t be soon; I’ve been completely swamped lately. But someday?

That would be great. The initial values for the inverse projection are also good initials for the inverse Chamberlin projection, although I'm not sure the time savings would be significant enough to bother.

[dummy_index]

Excellent work. Love it!

Thanks!

Does the point on the map where the two hemispheres touch correspond to the same point on the globe in each hemisphere?

Should be okay, ... Oh, I found a fix omission on GitHub.
In the general case, we need to find the angle of the tangent and place it ... I don't want to go that far.

I tried to arrange it in the north up without considering about touching.

TwoCurlyHemisphereA_NorthUp.png (81.79 KiB) Viewed 1709 times

[PeteD]

Hmm, I think I preferred the first version with the axes of the boundary aligned horizontally and vertically.

If you allow cutting through some more small islands, is it possible to align the vertical axes of the boundary in the north-south direction? After all, the boundary already cuts through one of the Aleutian Islands, and as long as it doesn't cut through any landmasses larger than, say, Crete, the split islands probably won't be noticeable on a world map anyway.

[dummy_index]

If you allow cutting through some more small islands, is it possible to align the vertical axes of the boundary in the north-south direction?

Maybe no. With condition passing through Bering Strait and east side of Iceland, cutting the New Zealand is inevitable.

TwoCurlyHemisphereG.png (82.58 KiB) Viewed 1685 times

Or cut Iceland? (Passing through west side of Iceland seems to be impossible.)

TwoCurlyHemisphereH.png (84.3 KiB) Viewed 1685 times

Or cut Chukchi Peninsula?

TwoCurlyHemisphereI.png (82.19 KiB) Viewed 1685 times

[dummy_index]

cutting is tilted only 3°, and projected boundary is aligned horizontally and vertically.
North/South Americas *look like* north-up.

TwoCurlyHemisphereF.png (81.57 KiB) Viewed 1676 times

[brsr]

I read your paper a while ago; sorry that I did not get back to you about it. It’s a good paper. Do you intend to publish?

I had a busy spring, but I'm finally getting back around to submitting it.

It's published now: A variation on the Chamberlin trimetric map projection. If anyone doesn't have institutional access the preprint is still on the GitHub repo. That was... actually a much faster process than I thought it was going to be! Is this still experimental if it's published?

Would be interesting to apply this (and Chamberlin) to a butterfly-style map.

[PeteD]

A palm tree:

bartholomew_regional_palm_tree.png (120.94 KiB) Viewed 1542 times

and either a flower missing a couple of petals or a windmill missing a couple of blades:

bartholomew_regional_windmill.png (111.87 KiB) Viewed 1542 times

Both 5-lobe variants of the Bartholomew regional projection.

Please ignore the lines connecting the different parts of Antarctica.

[Atarimaster]

Hi Peter,

nice work!
I like them both, especially the windmill.
Try selling the palm tree variant to a travel agency!

Kind regards,
Tobias

[Atarimaster]

Try selling the palm tree variant to a travel agency!

For that matter, maybe I should try to sell this equal-area projection to a manufacturer of underwear?