Are streameuler2d, streameuler3d internal functions?

[Rik]

All,

I'm working on the documentation for the 6.1 release and checking that
every function that should be listed in the manual, is listed in the manual.

Does anyone know know enough about streameuler2d and streameuler3d to say
whether they are internal functions or not?  These functions are used by
the m-files streamline, stream2, stream3, and streamtube which makes me
think they are internal and could be renamed to have a leading "__" and
trailing "__".

--Rik