Mapthematics Forums

This could be one of those "the only way to determine the projection is to somehow duplicate a distorted scan of a centuries-old publication". Which is always tons of fun for carto nerds. If you get 90%+ of the way there, you can claim la victoire.

Yes, very similar, but not quite the same. The Bonne projection with phi_TS at about 17°N unsurprisingly also looks very similar.

I saw a toot on Mastodon tonight about the "Fool's Cap" projection, which seems to actually be a couple different projections shown within the face of a Renaissance fool, depending on the version you encounter. The art dates back to the late 1500s. The original such illustration uses the O...

I have worked on the general case of Tobler's Hyperelliptical, allowing the user to specify all three parameters, and recently. But the results have been unsatisfactory. Even when the output map comes out looking good, rendering time can be sluggish. Even rendering Tobler's preferred case is a bit ...

My original goal in writing that program was to explore the Tobler hyperelliptical projection better than available tools let me do. NASA's G.Projector, which I usually use, does include the Tobler projection, but does not allow variation of the exponent (presumably, it's hardcoded to use the 2.5 v...

I'd be very interested if anyone knows the answer or can provide formulae for Snyder's projections. Snyder's two minimum-error projections are in his 1985 USGS bulletin report, " Computer-Assisted Map Projection Research ". Flat-pole is equations 5-176, 5-177 and 5-179, using the values o...

Regrettably, I don’t have the paper but regarding the appearance: Earlier in Minimum distortion pointed-polar projections Györffy says: “pseudocylindrical with minimized distortion, labelled as ‘version (c)’ later, formulae in Györffy, 2016, p. 264”. So I think that the projection he refers to in y...

I agree that the map center looks equidistant (as far as one can tell from the image) rather than equal-area like in William-Olsson. Maybe a four-lobe variant of the Hexafoliate Equidistant , i.e. a “Tetrafoliate Equidistant”? I don’t know who developed the Hexafoliate Equidistant so I can’t check ...