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[Andy Waddington on Survey stuff]

Wookey discusses fixes to turn off "Fixed point not used" and/or "point
already fixed" errors.

I think there is a philosophy error in Survex (!). Just because there is no
survey fixed to a fixed point doesn't mean that a fixed point isn't used !
Maybe the fixed point was put in so that the (human) user could use it ?
This is what I do all the time - I want the entrances shown, but not the
surface survey which fixed them. So the entrance coordinates are all *FIXed
from a previous run of Survex. The same could apply to any kind of useful
landmark points fixed by neans outside's Survex's scope (like a professional
land survey, or GPS coordinates). The user wants to know where they are, and
wants them in the 3d file, but doesn't have any reason to connect a survey
to them.

I feel that *FIX should *never* generate a not used error, but
perhaps we could invent a sensible name for a

*FIX_AND_TELL_ME_IF_NOTHING_CONNECTS_HERE ... command

Connected with the same problem that prompted Wookey to devise this
hack is the "Point already fixed at the same coordinates" error.
So what ? If I think the point is in the same place as I thought it
was before, that's fine, just get on with it. If for some reason
(and I can't imagine one at the moment) you actually want this
warning, then we should invent a

*FIX_UNIQUELY directive or something similar.

Of course, if I am *FIXing something at _Different_ coordinates then
I do want a warning.

One workaround for the "fix not used" error is to add a zero-length survey
leg to each fixed point - messy, but then it depends whether you are happier
ignoring kludges in your data, or screeds of ignorable warnings. Ignoring
warnings in transient output is not a problem, until there is a single error
hidden somewhere in the great screed of warnings that scroll past.

Andy