Mapthematics Forums

Many of the 16th century projections were ad hoc. I don’t know if that exact one shows up in other contexts. I can speculate on what influenced its design, but I don’t know of any description for its construction.

— daan

The variant you link to is something along the lines of the modified ptolemaic projection used by Waldseemüller in his very famous 1507 map of the world as the first showing “America”.

Cheers,
— daan

Apologies for the long delay.

Thank you, Bill, for the solidarity. I still have not settled on a course of action. I’ll note when I do.

— daan

Hello Maezar. You have several choices in Geocart: • Chaise lounge • Dymaxion-like conformal • Polyhedron conformal face • Gnomonic In the case of the dymaxion-like conformal, a couple of the faces have been split and moved; you may need to reassemble them. In the case of the polyhedron conformal fa...

quadibloc wrote: ↑Wed Jun 05, 2024 7:24 pm Oddly, though, you refer to Pafnuty Chebyshev, as if he wasn't the Chebyshev, who hardly needs to be described further, but simply refer to the one who then proved that conjecture simpy as Grave.

The parameters in the paper only approximate a 2:1 astroid; it does not give me the exact 2:1 shape. I'm a pixel counter. Is there an easy way to figure out what those exact parameters would be? Mathematical development hasn't been my strong suit. Being equal-area, you can stretch it in one directi...

Is the main goal of the legislation to remove the Mercator or to promote the Gall–Peters? The original bill restricted use to either Gall–Peters or Authagraph. What got signed into law was watered down a little to permit other rectangular equal-area projections as well. I think we can conclude that...

I didn’t realize the van der Grinten IV could be parameterized, having never really scrutinized the method. Thanks for the tutorial on your site. I agree that the 270° form is an improvement in the uninterrupted form. As far as interruptions go, I don’t like seeing Eurasia split up, so I would apply...

It is my pleasure to introduce the Chalker-Peters composite projection, featuring: Taking a break from other work to dive a little deeper with terminology, we can say: • It is not a projection, since it is created from existing projections, the identity of which is not fixed. • It is not an interru...

quadibloc wrote: ↑Sat Jun 01, 2024 8:15 am But the lack of originality was not its worst fault.

For me, the worst of it was the malice in Peters’s claims about cartographers’ malice in promoting the Mercator projection.

— daan