In my project course this fall I've got the exersice to
implement an analytic function in Grass based on fuzzy
logic. A major problem is to create a dataset where a
membershipdegree ( ex. an integer value between 0 and 10)
is assigned to each pixel in the map. So I wonder whether
the data format in Grass maps allows us to assign more
than one attribute value to a pixel ??
Thanks in advance
Frode Abrahamsen
frode@iko.unit.no
Frode Abrahamsen (frode@guran1.iko.unit.no) writes on 6 Mar 94:
In my project course this fall I've got the exersice to
implement an analytic function in Grass based on fuzzy
logic. A major problem is to create a dataset where a
membershipdegree ( ex. an integer value between 0 and 10)
is assigned to each pixel in the map. So I wonder whether
the data format in Grass maps allows us to assign more
than one attribute value to a pixel ??
Trying using the category file. If pixels with the same
values have differing membership degrees, then you may
need to use two numbers in the category label:
c:n m
(where c, the category, is just used as an identifier,
n is the actual value
m is the membership degree)
Another way that is a little neater is to just use the reclass
facility:
map reclassed_map
c:n c:m
This would make it easier to use tools like r.mapcalc for your project.
The latter would definately be more recommended if you intend to
create a "product" (i.e., redistribute your work to others)
--Darrell
James Darrell McCauley, Purdue Univ, West Lafayette, IN 47907-1146, USA
mccauley@ecn.purdue.edu, mccauley%ecn@purccvm.bitnet, pur-ee!mccauley
** will finish PhD/engr in 9/94 - need job. inquiries welcome (no hh, plz) **
I do something simmilar. I assign to each pixel the probability of being
assigned to several vegetation classes. This is the output of a discriminant
analysis. I do it creating a cats file.
Agus