[gdal-dev] weeding out x,y,z points

[nicholas.g.lawrence at mainroads.qld.gov.au]

> nicholas.g.lawrence at mainroads.qld.gov.au wrote:
> > A client has a very large (millions of records) ascii file consisting
> > solely of x,y,z co-ordinates.
> >
> > They would like to reduce the number of records by weeking out points
that
> > are too close to each other.
> >
> > Can GDAL or OGR weed out 3D points based on proximity to each other?

>
> A job for GMT's blockmean or blockmedian.

> Joaquim Luis

Okay, I downloaded the Manpages.

My initial reading is that blockmean and blockmedian work by averaging
the values.

My client says that they want the resulting data points to be
a subset of the original data points, that is the process should
delete points, not re-calculate new ones that are an average.

Is this still do-able? Is there a specific option I should
be looking at?

Regards,
nick


***********************************************************************
WARNING: This e-mail (including any attachments) may contain legally
privileged, confidential or private information and may be protected by
copyright. You may only use it if you are the person(s) it was intended
to be sent to and if you use it in an authorised way.  No one is 
allowed to use, review, alter, transmit, disclose, distribute, print 
or copy this e-mail without appropriate authority.

If this e-mail was not intended for you and was sent to you by mistake,
please telephone or e-mail me immediately, destroy any hardcopies of
this e-mail and delete it and any copies of it from your computer
system. Any right which the sender may have under copyright law, and 
any legal privilege and confidentiality attached to this e-mail is not 
waived or destroyed by that mistake.

It is your responsibility to ensure that this e-mail does not contain
and is not affected by computer viruses, defects or interference by
third parties or replication problems (including incompatibility with
your computer system).

Opinions contained in this e-mail do not necessarily reflect the
opinions of the Queensland Department of Main Roads, Queensland
Transport or Maritime Safety Queensland, or endorsed organisations
utilising the same infrastructure.
***********************************************************************