[GRASS5] Re: MASK in GRASS 5;.7

[Paul Kelly]

Hello Michael

On Sun, 18 Apr 2004, Michael Barton wrote:

> This is a relief.
>
> This is a simple procedure to name (or copy) any raster map to MASK. A
> couple of questions.
>
> 1. Is this the same kind of binary map as is used in GRASS 5.3? That
> is, operations take place in grid squares with a MASK value of 1, while
> those with a MASK value of 0 are ignored.

There is absolutely no difference between 5.3 and 5.7 for raster
processing operations. The code is copied over from 5.3 and is exactly the
same. In both 5.3 and 5.7, the MASKed cells can be either 0 or null and
the un-masked cells any other value (I'm not sure if I've seen that
documented anywhere but that's my experience anyway). I've never used
r.mask; always found it much easier to do g.copy rast=xxx,MASK.

>
> 2. Does the name have to be in all caps (i.e., MASK vs. Mask or mask)?

Yes. Only MASK will work.


Paul