Finding the rectangular domain that covers an oblique area

Q&A
8

As Paul wrote, this is now implemented. And I can do this:

gmt mapproject -JS36/90/30c -R-15/60/68/90 -WE
-R-1.852421104674526/62.33269965938534/126/80.96267731894207+r

which answers my question. Slick.