[GRASS-user] cells with undefined aspect

GRASS GRASS user
1

Speaking of slope/aspect, what do you guys think is the best approach
with cell of undefined aspect (zero slope)?
In this all roughness study I am doing, there are some nice methods
working with vector orientation. So I use aspect - compass azimuth -
but what about those cells with zero slope? should I make them to have
what aspect? zero? 360? NULL?

cheers

--
+-----------------------------------------------------------+
              Carlos Henrique Grohmann - Guano
  Visiting Researcher at Kingston University London - UK
  Geologist M.Sc - Doctorate Student at IGc-USP - Brazil
Linux User #89721 - carlos dot grohmann at gmail dot com
+-----------------------------------------------------------+
_________________
"Good morning, doctors. I have taken the liberty of removing Windows
95 from my hard drive."
--The winning entry in a "What were HAL's first words" contest judged
by 2001: A SPACE ODYSSEY creator Arthur C. Clarke

2

"Carlos \"Guâno\" Grohmann" wrote:

Speaking of slope/aspect, what do you guys think is the best approach
with cell of undefined aspect (zero slope)?
In this all roughness study I am doing, there are some nice methods
working with vector orientation. So I use aspect - compass azimuth -
but what about those cells with zero slope? should I make them to have
what aspect? zero? 360? NULL?

Cells with zero slope should have null for the aspect.

--
Glynn Clements <glynn@gclements.plus.com>

3

Personally I prefer to use the NULL value (or -1, for example). Note that
aspect has no sense in a slope zero area so it is a good idea to use a
singular value for a exceptional situation. That's my view

-----Mensaje original-----
De: grassuser-bounces@grass.itc.it [mailto:grassuser-
bounces@grass.itc.it] En nombre de Carlos "Guâno" Grohmann
Enviado el: miércoles, 04 de julio de 2007 15:46
Para: grass user
Asunto: [POSIBLESPAM]: [GRASS-user] cells with undefined aspect

Speaking of slope/aspect, what do you guys think is the best approach
with cell of undefined aspect (zero slope)?
In this all roughness study I am doing, there are some nice methods
working with vector orientation. So I use aspect - compass azimuth -
but what about those cells with zero slope? should I make them to have
what aspect? zero? 360? NULL?

cheers

--
+-----------------------------------------------------------+
              Carlos Henrique Grohmann - Guano
  Visiting Researcher at Kingston University London - UK
  Geologist M.Sc - Doctorate Student at IGc-USP - Brazil
Linux User #89721 - carlos dot grohmann at gmail dot com
+-----------------------------------------------------------+
_________________
"Good morning, doctors. I have taken the liberty of removing Windows
95 from my hard drive."
--The winning entry in a "What were HAL's first words" contest judged
by 2001: A SPACE ODYSSEY creator Arthur C. Clarke

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