Clarification for project
|Affected version:||5.1.x||Platform:||Mac OS X|
I am reporting back on something that stumped me in using gmt project. I noticed this issue when using the -G generate mode. The model uses -C to define the center of the projection, which is defined where p,q = 0,0. However, I find that when I specify a length for small circle, using -L and -Q, the length is defined as if the center is at the oblique equator. Of course, -G does not work for a small circle unless the colatitude is appended to the -G option.
I include an example below to demonstrate this issue. My opinion is that it would be better for the user to follow the concepts associated with a map projection. As such, I view the oblique projection provided by project to be defined relative to a central oblique meridian and a central oblique parallel. My intuition suggests that -C defines the lon, lat point where those two features cross. Alternatively, maybe -C is meant to mean the start of a path, in which case, it is no longer relevant to the center or origin of the projection.