function arcRadius
entryArc.ts:121
Distance from the center at an angle psi from apoapsis.
On the radial line the angle means nothing and the radius is not a function
of it; callers there parametrize by radius through arcAnomaly, which is
the identity map, and this returns the apoapsis so a caller that asks
anyway gets the one radius the line is certain about.
- arcEntryArc
- Undocumented
- psinumber
- Undocumented
Returnsnumber