cat file for r.mapcalc

Malcolm Williamson malcolm at
Fri Oct 13 17:16:23 EDT 1995

On 13 Oct 1995, Xin Zhuang wrote:

> I have two layers: left and right. They don't overlay.
> I'd like to merge them together. Guess I can use
> either
> 	new = left + right
> or more safely
> 	new=if(left,left,right)
> However, there won't be category contents for Layer "new".
> Is there a way to bring category contents in Layers "left"
> and "right" into Layer "new"?
> Or maybe I should use another function?
> Appreciate any hint and help.

I believe that r.patch will retain category labels as long as they are 
unique; it _does_ retain colors for unique categories. Check it out!
Malcolm D. Williamson - GIS Specialist           E-mail: malcolm at
Center for Advanced Spatial Technologies      Telephone: (501) 575-6159
Ozark Rm. 12                                        Fax: (501) 575-5218 
University of Arkansas              
Fayetteville, AR 72701

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