Bedding planes, rose diagrams and bug fix

[Phil Underwood]

I'm thinking about making a couple of analysis tools for survex/chasm.
One is a rose diagram - showing the comparative frequency of directions o=
f
legs. I've got a pretty basic one set up; are there any more features tha=
t
people would appreciate? (eg weighting the relative contribution of legs =
by
their length, excluding very short legs)

Do people think that these kind of widgets are a good idea, or just
pointless bells and whistles for what should be a lean mean cave-displayi=
ng
machine?

The other thing I'm currently thinking about is a gadget that will search
through the legs in a survey, looking for any planes whcih seem to contai=
n
a lot of legs eg a phreatic level or a fault controlling the cave formati=
on.

I've currently got to the stage where I can lots of slices through the ca=
ve
and see if any have more legs in them than expected. What I would then ne=
ed
to do would be to take all these vectors and somehow take an average of
these, turning it into a plane equation.

The only thing I can come up with is taking the cross-product of two
successive vectors, and summing all these cross-products together.
Unfortunately, this would mean that the last leg of an odd number of legs
should be ignored. Anyone got a better way of doing this? I don't really
know much about linear algebra/ vector calculus /geometry so I would
appreciate some input from anyone who knows this kind of stuff.

BUG REPORT: My last edition of Chasm for Win32 came with non-working
versions of cavern and cextend. This is now fixed on the Chasm web-site.
Another bug caused cavern to output *extremely* long station names in 3dx
files. This is also fixed, with a small patch again from the Chasm web-si=
te.

I appear to have waffled on for far too long now, so I'll shut up.
--=20
Phil Underwood <furbrain@furbrain.screaming.net>
Chasm's Homepage: http://members.xoom.com/bighairyone/chasm/
"It's not what you've got, it's how you make it explode."