Mollweide map projection and Newton's method(johndcook.com)
johndcook.com
Mollweide map projection and Newton's method
https://www.johndcook.com/blog/2025/09/21/mollweide-newton/
6 comments
If you want to avoid the double root you could also solve for sin(2t). The derivative of the arcsin is simpler if anything.
You may need some special handeling for sin(2t)=1 still. You could pretend the funtion continues there (just join it together with asin(z - 1) + z - 1 + pi/2). Or maybe some other transformation.
You may need some special handeling for sin(2t)=1 still. You could pretend the funtion continues there (just join it together with asin(z - 1) + z - 1 + pi/2). Or maybe some other transformation.
Unfortunately I don't know how to think about the Mollweide projection https://xkcd.com/977/
That comic is never not funny. Classic XKCD.
That doesn't look like the image. If you're looking at Earth from a distance, there will be foreshortening that squishes the meridians together. But the meridians look almost evenly spaced except for the far left and right edges of the ellipse.