r.slope.aspect

[Michael Shapiro]

The interactive verion and the manual have not been updated. I have
reported this as a "bug" to be fixed. r.slope.aspect was upgraded
to do 360 of aspect. The manuals and interactive versions may have been
overlooked (if not, they certainly weren't put on the ftp site).

|
|
|I am using r.slope.aspect to reduce the possible 360 degrees of aspect
|down to 8 principle directions (N,NE,E,etc). When running the program
|r.slope.aspect interactively, the header tells me that the aspect
|output will be categorised into 24 directions, as does g.manual.
|However, the output is in 360 categories.

You can use r.reclass command line version very easily, if you use
the command line version. You would do something like this:
	r.reclass i=aspect o=aspect.8
	1 thru 45 = 1
	46 thru 90 = 2
	91 thru 135 = 3
	136 thru 180 = 4
	181 thru 225 = 5
	226 thru 270 = 6
	271 thru 315 = 7
	316 thru 360 = 8
	end

You probably need to use a differnent set of rules since you want N,NE, etc.
but they wouldn't be har to work out and once you have them, save them in a file
and run r.reclass like this:
	r.reclass i=aspect o=aspect.8 < aspect.rules



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Michael Shapiro                        U.S. Army CERL                  
email:   shapiro at amber.cecer.army.mil  Office of GRASS Integration
phone:   (217) 373-7277                P.O. Box 9005                   
fax:     (217) 373-7222                Champaign, Ill. 61826-9005
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