Fuzzy data set

James Darrell McCauley mccauley at ecn.purdue.edu
Sun Mar 6 12:57:59 EST 1994


Frode Abrahamsen (frode at 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 at ecn.purdue.edu, mccauley%ecn at purccvm.bitnet, pur-ee!mccauley
** will finish PhD/engr in 9/94 - need job. inquiries welcome (no hh, plz) **



More information about the grass-dev mailing list