GRASS Raster Mask - Revision history

⚠️NikosA: Retouched, re-wording

2013-02-05T09:57:15Z

Retouched, re-wording

← Older revision		Revision as of 09:57, 5 February 2013
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	~~'''Q:''': I do not have the concept of mask. Please anybody help me in understanding mask. What is this?~~		{{NeedsExpansion}}

	'''A:''' A mask allows you to block arbitrary areas of all rasters processed while the mask is set. That is, for cells where the mask is set, those cells will be treated as if they were NULL. It was more important when GRASS didn't have a true concept of NULL value (GRASS 4.x), however, masks still can be useful even in GRASS 5.x

	~~Masking~~ can be even used in ps.map script, so a raster ~~mask~~ can applied to vector features that ~~one wants~~ to be masked~~, it~~ is ~~done~~ by the masked y\|n switch.		'''Question'''

			I don't understand the concept of the ''MASK''. What is it?

			'''Answer'''

			A MASK allows you to block arbitrary areas of all raster maps processed while the MASK is set. That is, those cells for which the MASK is set, will be treated as if they were NULL. Originally, it was important when GRASS didn't have a true concept for the ''NULL'' value (GRASS 4.x). It is, however, still very useful in all GRASS versions (5.x, 6.x and 7.x). MASKing can be even used inside a <code>ps.map</code> script. This way, a raster MASK can be applied to vector features that need to be masked. This is achievable by using the masked <code>y\|n</code> switch.

	[[Category:FAQ]]		[[Category:FAQ]]
	[[Category:Raster]]		[[Category:Raster]]
	[[Category:MASK]]		[[Category:MASK]]

⚠️NikosA: Categories: Raster, MASK

2013-02-05T09:48:25Z

Categories: Raster, MASK

← Older revision		Revision as of 09:48, 5 February 2013
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	[[Category:FAQ]]		[[Category:FAQ]]
			[[Category:Raster]]
			[[Category:MASK]]

Neteler at 20:00, 16 June 2006

2006-06-16T20:00:23Z

← Older revision		Revision as of 20:00, 16 June 2006
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	Masking can be even used in ps.map script, so a raster mask can applied to vector features that one wants to be masked, it is done by the masked y\|n switch.		Masking can be even used in ps.map script, so a raster mask can applied to vector features that one wants to be masked, it is done by the masked y\|n switch.

			[[Category:FAQ]]

⚠️Dassau at 07:49, 19 May 2006

2006-05-19T07:49:21Z

New page

'''Q:''': I do not have the concept of mask. Please anybody help me in understanding mask. What is this?

'''A:''' A mask allows you to block arbitrary areas of all rasters processed while the mask is set. That is, for cells where the mask is set, those cells will be treated as if they were NULL. It was more important when GRASS didn't have a true concept of NULL value (GRASS 4.x), however, masks still can be useful even in GRASS 5.x

Masking can be even used in ps.map script, so a raster mask can applied to vector features that one wants to be masked, it is done by the masked y|n switch.