> There is a small technical bug in "sub great_circle_destination {...}".
> An additional (optional) argument, RHO, must be passed to the
> subroutine. Otherwise, the calculation will always be based on theI am confused. On a sphere the destination point d (radians) one ends up after going from point a (radians) in direction b (radians) for c (radians) doesn't depend on the rho (radius) ... that's the beauty of radians, right? Or do you mean you want to specify the distance to travel in some units other than radians? > assumption that we are using a unit sphere. RHO will represent the > radius of the sphere. I have previously written a subroutine also named > great_circle_destination which may be of use to you :) The subroutine > assumes that the user is inputting coordinates in radians using the > following standards: We cannot change the default coordinate system of the great_circle_* routines. For better or worse, the pi/2 or 90 deg needed twist has been documented to work that way for quite some time now, we cannot change this without breaking people's code. See also the discussion in the documentation about the theta and phi: these is no one single "correct" spherical coordinate system. One possible way to incorporate your semantics would be to add an export tag, e.g. ":great_circle_latlon" that would affect the great circle formulas. >
