Hello,
I have tried to send part of this message before but I assume it did not
reach the list due to list-related problems, apologies if you have
received this before.
A colleague of mine is attempting to solve a problem that I'm hoping
users of GRASS may be able to help with.
My colleague is looking for software that will characterise the
complexity of the boundary of an area. That is, if the boundary of an
area had very `wiggledy' complex edges then it would be distinct from an
area of which the edges were very smooth. The ultimate aim is to
describe and compare the shape of different boundaries of enclosed areas
derived from an interpretation of remotely-sensed imagery.
I assume that a fractal-based approach would be a viable way to approach
this problem. I am wondering, therefore, if anyone is aware of any GRASS
programs, or indeed other software, that might be suitable for this purpose.
Also, has anyone heard of a GRASS module called r.le? Apprently, it is
used to quantify landscape metrics. If anyone could suggest where it
might be obtained I would apreciate the relevant information. Please
could you send any replies to my email address as well as to the list.
Thanks in advance,
Chris Lloyd
--
C.D.Lloyd
Department of Geography, Email: cdl195@soton.ac.uk
University of Southampton, Phone: +44 (0)1703 592205
Highfield, WWW: http://www.soton.ac.uk/~cdl195
Southampton,
SO17 1BJ,
England, UK
"C.D.Lloyd" wrote:
...
My colleague is looking for software that will characterise the
complexity of the boundary of an area. That is, if the boundary of an
area had very `wiggledy' complex edges then it would be distinct from an
area of which the edges were very smooth. The ultimate aim is to
describe and compare the shape of different boundaries of enclosed areas
derived from an interpretation of remotely-sensed imagery.
I assume that a fractal-based approach would be a viable way to approach
this problem. I am wondering, therefore, if anyone is aware of any GRASS
programs, or indeed other software, that might be suitable for this purpose.
Hi Chris,
if he could output the boundary as an ASCII file consisting of
coordinate pairs,
he could run fd3 on this. Just do a (archie)search for "fd3". Some
people don't
like fd3 because it's based on box-counting but in this case it should
be perfect.
And it's VERY fast. Btw., yes, fd3 estimates fractal dimensions.
Regards,
Christian
Dr. Christian Goltz
Institut fuer Geowissenschaften, Abt. Geophysik, Univ. Kiel
Olshausenstr. 40 - 60, D-24098 Kiel, Germany
Tel. +49-431-880-3881, Fax -4432, mailto:goltz@geophysik.uni-kiel.de
http://www.geophysik.uni-kiel.de/goltz/
r.le is included in the standard GRASS package, for what its worth.
It does fractal dimension, at least as far as I remember.
Angus Carr.
Chris,
Have you considered a simple perimeter/area index? You can use v.report
to output these numbers.
Regards,
-Malcolm Williamson
"C.D.Lloyd" wrote:
Hello,
I have tried to send part of this message before but I assume it did not
reach the list due to list-related problems, apologies if you have
received this before.
A colleague of mine is attempting to solve a problem that I'm hoping
users of GRASS may be able to help with.
My colleague is looking for software that will characterise the
complexity of the boundary of an area. That is, if the boundary of an
area had very `wiggledy' complex edges then it would be distinct from an
area of which the edges were very smooth. The ultimate aim is to
describe and compare the shape of different boundaries of enclosed areas
derived from an interpretation of remotely-sensed imagery.
I assume that a fractal-based approach would be a viable way to approach
this problem. I am wondering, therefore, if anyone is aware of any GRASS
programs, or indeed other software, that might be suitable for this purpose.
Also, has anyone heard of a GRASS module called r.le? Apprently, it is
used to quantify landscape metrics. If anyone could suggest where it
might be obtained I would apreciate the relevant information. Please
could you send any replies to my email address as well as to the list.
Thanks in advance,
Chris Lloyd
--
C.D.Lloyd
Department of Geography, Email: cdl195@soton.ac.uk
University of Southampton, Phone: +44 (0)1703 592205
Highfield, WWW: http://www.soton.ac.uk/~cdl195
Southampton,
SO17 1BJ,
England, UK
On Thu, 8 Jul 1999, C.D.Lloyd wrote:
My colleague is looking for software that will characterise the
complexity of the boundary of an area. That is, if the boundary of an
area had very `wiggledy' complex edges then it would be distinct from an
area of which the edges were very smooth. The ultimate aim is to
describe and compare the shape of different boundaries of enclosed areas
derived from an interpretation of remotely-sensed imagery.
The way we do it in ecology is to calculate the ratio of perimeter to
area. The higher the number the more irregular the edge. You need to
calibrate it for your purposes. Quick and easy to do. Even a spreadsheet
will work.
Rich
Dr. Richard B. Shepard, President
Applied Ecosystem Services, Inc.
2404 SW 22nd Street
Troutdale, OR 97060-1247 U.S.A.
+ 1 503-667-4517 (voice) | + 1 503-667-8863 (fax)
rshepard@appl-ecosys.com
Making environmentally-responsible mining happen.
Hello,
A friend just reminded me about and forwarded the website for downloading
software that might be appropriate to your goals. See FRAGSTATS @:
http://blaze.innovativegis.com/products/fragstatsarc/
alynne.
"C.D.Lloyd" wrote:
Hello,
I have tried to send part of this message before but I assume it did not
reach the list due to list-related problems, apologies if you have
received this before.
A colleague of mine is attempting to solve a problem that I'm hoping
users of GRASS may be able to help with.
My colleague is looking for software that will characterise the
complexity of the boundary of an area. That is, if the boundary of an
area had very `wiggledy' complex edges then it would be distinct from an
area of which the edges were very smooth. The ultimate aim is to
describe and compare the shape of different boundaries of enclosed areas
derived from an interpretation of remotely-sensed imagery.
I assume that a fractal-based approach would be a viable way to approach
this problem. I am wondering, therefore, if anyone is aware of any GRASS
programs, or indeed other software, that might be suitable for this purpose.
Also, has anyone heard of a GRASS module called r.le? Apprently, it is
used to quantify landscape metrics. If anyone could suggest where it
might be obtained I would apreciate the relevant information. Please
could you send any replies to my email address as well as to the list.
Thanks in advance,
Chris Lloyd
--
C.D.Lloyd
Department of Geography, Email: cdl195@soton.ac.uk
University of Southampton, Phone: +44 (0)1703 592205
Highfield, WWW: http://www.soton.ac.uk/~cdl195
Southampton,
SO17 1BJ,
England, UK
GRASS users,
The web address given below for FRAGSTATS is not as pertinent to GRASS
users since it a site offering a modified version of FRAGSTATS geared
toward ArcInfo users.
However, the original FRAGSTATS is available in both a raster and an
ArcInfo vector version. It is a great software and I have found it very
useful. The official? web location for FRAGSTATS is
http://www.fsl.orst.edu/lter/datafr.htm -and follow the "Software" link.
Jeff P. Hollenbeck
Dept. of Forest Resources
Oregon State University
Corvallis, OR 97331
hollenbj@ucs.orst.edu
On Fri, 16 Jul 1999, alynne bayard wrote:
Hello,
A friend just reminded me about and forwarded the website for downloading
software that might be appropriate to your goals. See FRAGSTATS @:
http://blaze.innovativegis.com/products/fragstatsarc/
alynne.
"C.D.Lloyd" wrote:
> Hello,
>
> I have tried to send part of this message before but I assume it did not
> reach the list due to list-related problems, apologies if you have
> received this before.
>
> A colleague of mine is attempting to solve a problem that I'm hoping
> users of GRASS may be able to help with.
>
> My colleague is looking for software that will characterise the
> complexity of the boundary of an area. That is, if the boundary of an
> area had very `wiggledy' complex edges then it would be distinct from an
> area of which the edges were very smooth. The ultimate aim is to
> describe and compare the shape of different boundaries of enclosed areas
> derived from an interpretation of remotely-sensed imagery.
>
> I assume that a fractal-based approach would be a viable way to approach
> this problem. I am wondering, therefore, if anyone is aware of any GRASS
> programs, or indeed other software, that might be suitable for this purpose.
>
> Also, has anyone heard of a GRASS module called r.le? Apprently, it is
> used to quantify landscape metrics. If anyone could suggest where it
> might be obtained I would apreciate the relevant information. Please
> could you send any replies to my email address as well as to the list.
>
> Thanks in advance,
>
> Chris Lloyd
>
> --
> C.D.Lloyd
> Department of Geography, Email: cdl195@soton.ac.uk
> University of Southampton, Phone: +44 (0)1703 592205
> Highfield, WWW: http://www.soton.ac.uk/~cdl195
> Southampton,
> SO17 1BJ,
> England, UK