[GRASSLIST:2336] Re: Removing a section of a raster map

[Rich Shepard]

On Wed, 8 Aug 2001, Hal Mueller wrote:

> hammer #2:  v.digit, using the original data as an underlying cell
> map, generate a polygon around the incorrect areas, build mask from
> that vector region

  I'm part way there, but missing a step and I don't know what it is.

  The key was using Customize | Background image in the v.digit menu to put
the raster, wart and all, on display. Then I zoomed in on the region,
digitized and quit. (Why it told me 2 more nodes were needed -- beyond the
five there -- I've no idea.) Ran v.support on the little rectangle. Looks
cute and is in the proper place (checked that already).

  Now comes the missing step.

  Using the vector file as input, I ran v.to.rast and assigned the output to
'mask'. OK so far. But, when I display 'mask', it covers the entire region
of the original map, not just the little digitized rectangle. Why?

Thanks,

Rich

Dr. Richard B. Shepard, President

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