your mail

[Craig A. Miller]

On Thu, 14 Oct 1993, Megan Stewart wrote:

> Newsgroups: info.grass.user
> Path: copeland
> From: copeland at lamar.ColoState.EDU (Jeffrey Copeland)
> Subject: MASKS
> Sender: news at yuma.ACNS.ColoState.EDU (News Account)
> Message-ID: <Oct11.143811.18889 at yuma.ACNS.ColoState.EDU>
> Date: Mon, 11 Oct 1993 14:38:11 GMT
> Nntp-Posting-Host: lamar.acns.colostate.edu
> Organization: Colorado State University
> Lines: 14
> 
> 
> I'm trying to create a MASK for a hand drawn area.  I can see how to
> take a vector area and get a raster file from that, but how do I get
> the raster file to have 2 categories, 1 inside mask line and the other
> outside.  
> 

Two ways:

1. Generate the mask from a vector file with
	0 for nodata
	1 for mask area
   and then generate your raster file with v.to.rast

2. Use r.reclass on your current raster file that you want to use and set all
   of the categories that you want included in your mask to 1, and set all of
   those that are outside of the mask (Area that will no be visible in the end) to
   a 0.


E-mail me privately if you have any trouble.

Take Care,

Craig Miller
GIS Coordinator
Chelan County Conservation District
cmiller at pnwg.wa.com