removing duplicate vectors

Dave Gerdes dpgerdes at
Wed Jan 20 15:47:24 EST 1993

> A small program to remove duplicate vectors in a binary
> vector file is available via anonymous ftp at
> It should be considered pre-alpha, but it works on my test files.
> So far, it only removes vectors that are exact duplicates
> (all points are the same within threshold, within IEEE "wobbling 
> precision" tolerance. see iszero(3)), but in the future
> I hope to add a threshold option which will increase this
> the tolerance to remove "similar" vectors.
> Use at your own risk (read the man page on g.copy first).
> --Darrell McCauley

For the record v.spag also does that.  4.0 had a rather nasty bug
in it, but in 4.1 it has been fixed and a -i option has been
added to tell it to just do that one function.

Now if you get the 'similar' feature working, lemme know. I can
come up with a bunch of cases to test it on.


  Dave Gerdes
  US Army Construction Engineering Research Lab
  Spatial Analysis & Systems Team
  dpgerdes at
  (217) 352-6511 x591

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