[GRASSLIST:2330] Re: Removing a section of a raster map

[Rich Shepard]

On Thu, 9 Aug 2001, Michel Wurtz wrote:

> Try v.digit on a new (empty) vector file, with your raster map as background.
> You can maunally draw a rectangular area around your data, without the
> protusion.
> dont forget to give a label to your area (1 is good), run v.support and
> v.to.rast.
> You should now have a mask that you can use with r.mapcal: output = input * mask

Michel,

  I believe that this is what I tried. With the raster map displayed in the
monitor, I invoked v.digit. Went through the questions on the screens and
told it to do only the border (not the internal "edges"). As soon as I
regained control, the raster map had been cleared from the monitor and a
thin, white vertical line near the center was present. The vertical line may
have been the right side of a rectangle because it looked like other lines
were along the top, left, and bottom of the monitor window.

  When the raster image displays in the monitor, it is centered
horizontally and has space on either side. Why it disappeared when I invoked
v.digit I cannot say. For that matter, as I was watching the window with the
v.digit setup I cannot even tell you just when the monitor changed.

Thanks,

Rich

Dr. Richard B. Shepard, President

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