[semi-extrinsic]

I just had a look at the Fortran code, and oh boy, it's not pretty, and far from "canonical" Fortran. I will submit a PR (hopefully later tonight) that makes it less ugly and slow.

(Protip: don't use if's inside tight loops. Just don't.)

[semi-extrinsic]

Update: just sent you a PR that reduces the amount of code by ~70% while increasing the speed by ~30% for the Fortran version.

[marblestation]

Merged! Thank you very much :-)