Error in loop closure algorithm?
olly at survex.com
Wed Aug 11 23:16:26 BST 2004
On Wed, Aug 11, 2004 at 11:04:43PM +0100, Mike McCombe wrote:
> Survex moves not only the survey legs in the "bad" loop but also
> adjusts the connecting leg (i.e. test.4 - test.5) and moves the
> station in the "good" loop (i.e. test.4) where the connecting leg
> joins. The "error" is only 1cm which wouldn't show in most cave
> surveys (with me using the instruments!) . However, the error is still
> 1cm if you scale the loops down to, say, 1m per leg - which becomes
> quite noticeable when the loops are small and generally well-closed.
I'm not seeing this on Linux with Survex 1.0.31. If I run the second
example through cavern and then 3dtopos, I get these coordinates:
( 0.00, 0.00, 0.00 ) test.1
( 10.00, 0.00, 0.00 ) test.2
( 10.00, -10.00, 0.00 ) test.3
( 0.00, -10.00, 0.00 ) test.4
( -10.00, -10.00, 0.00 ) test.5
( -10.00, -0.42, 0.00 ) test.6
( -20.00, -1.50, 0.00 ) test.7
( -20.00, -8.92, 0.00 ) test.8
What operating system are you using? And which version of Survex?
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