Contour lines to DEM - Revision history

Neteler: +hint about MASK

2015-06-03T15:59:34Z

+hint about MASK

← Older revision		Revision as of 15:59, 3 June 2015
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	== r.surf.contour ==		== r.surf.contour ==

	GRASS's {{cmd\|r.surf.contour}} module is specifically built for converting contour lines into DEMs, and in general it does a rather nice job at it.		GRASS GIS' {{cmd\|r.surf.contour}} module is specifically built for converting contour lines into DEMs, and in general it does a rather nice job at it.

			'''Important''': be sure to restrict the [[computational region]] to the area of interest, otherwise computations will be slow. You can also set a raster MASK with {{cmd\|r.mask}} in order to reduce the interpolation.

	[[Image:Contour1m_surf_scontr.png\|thumb\|600px\|center\|r.surf.contour]]		[[Image:Contour1m_surf_scontr.png\|thumb\|600px\|center\|r.surf.contour]]

Neteler: /* r.surf.contour */

2015-06-02T10:16:12Z

r.surf.contour

← Older revision		Revision as of 10:16, 2 June 2015
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	Some thatching artifacts are visible, but otherwise the module represents the surface well and does a good job recreating the river valleys and is the only one of the methods to successfully recreate the road running along the ridge on the upper-left edge of the image. Compare the two tendon-like roads running left-right across the valley with e.g. the TIN from ''r.surf.nnbathy''.		Some thatching artifacts are visible, but otherwise the module represents the surface well and does a good job recreating the river valleys and is the only one of the methods to successfully recreate the road running along the ridge on the upper-left edge of the image. Compare the two tendon-like roads running left-right across the valley with e.g. the TIN from ''r.surf.nnbathy''.

	A little extra work is needed to overcome the integer-only aspect of it, but that only takes a minute with {{cmd\|r.mapcalc}} as shown below.		'''Pre-GRASS GIS 6.4.1 only''': A little extra work is needed to overcome the integer-only aspect of old r.surf.contour versions, but that only takes a minute with {{cmd\|r.mapcalc}} as shown below.

	Commands used:		Commands used:
	<source lang="bash">		<source lang="bash">
	r.mapcalc "elev.1mcont.100k = elev.1mcont * 100000"		r.mapcalc "elev.1mcont.100k = elev.1mcont * 100000"

	r.surf.contour in=elev.1mcont.100k out=elev.1mcont.surf.100k		r.surf.contour in=elev.1mcont.100k out=elev.1mcont.surf.100k

	r.mapcalc "elev.1mcont.surfcont = elev.1mcont.surf.100k / 100000.0"		r.mapcalc "elev.1mcont.surfcont = elev.1mcont.surf.100k / 100000.0"

	g.remove elev.1mcont.surf.100k		g.remove elev.1mcont.surf.100k
	r.colors elev.1mcont.surfcont col=haxby		r.colors elev.1mcont.surfcont col=haxby
	</source>		</source>

	* In GRASS 6.4.1 and newer floating-point maps are supported so the above integer work-around is not needed.		Again, this is not needed with recent versions of r.surf.contour.

	== Reference images ==		== Reference images ==

Neteler: /* v.surf.bspline */ fix typo

2015-03-22T17:58:30Z

v.surf.bspline: fix typo

← Older revision		Revision as of 17:58, 22 March 2015
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	{\|		{\|
	\|[[Image:Contour1m_vspline_bil.png\|thumb\|300px\|left\|v.surf.~~vspline~~ bilinear interpolation using default parameters]][[Image:Contour1m_vspline_bic.png\|thumb\|300px\|right\|v.surf.~~vspline~~ bicubic interpolation using default parameters]]		\|[[Image:Contour1m_vspline_bil.png\|thumb\|300px\|left\|v.surf.bspline bilinear interpolation using default parameters]][[Image:Contour1m_vspline_bic.png\|thumb\|300px\|right\|v.surf.bspline bicubic interpolation using default parameters]]
	\|}		\|}

Neteler: + DEM to contour lines

2014-09-02T11:28:39Z

+ DEM to contour lines

← Older revision		Revision as of 11:28, 2 September 2014
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	* [[Interpolation]]		* [[Interpolation]]
			* [[DEM to contour lines]]

	[[Category: FAQ]]		[[Category: FAQ]]

Neteler: /* See also */

2013-12-31T17:59:30Z

Neteler: /* Further investigation */

2013-11-24T10:47:30Z

Further investigation

← Older revision		Revision as of 10:47, 24 November 2013
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	pcurv=elev.1mcont.rst.pcurv tcurv=elev.1mcont.rst.tcurv		pcurv=elev.1mcont.rst.pcurv tcurv=elev.1mcont.rst.tcurv

			== See also ==

			* [[Interpolation]]

	[[Category: FAQ]]		[[Category: FAQ]]
	[[Category: Interpolation]]		[[Category: Interpolation]]
	[[Category: Documentation]]		[[Category: Documentation]]

⚠️Landa: /* r.surf.nnbathy (addons) */

2012-12-23T16:49:45Z

r.surf.nnbathy (addons)

← Older revision		Revision as of 16:49, 23 December 2012
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	== r.surf.nnbathy (addons) ==		== r.surf.nnbathy (addons) ==

	The next method we will look at is the {{AddonCmd\|r.surf.nnbathy}} add-on module. It performs a {{wikipedia\|~~Natural_neighbor~~}} interpolation. (see also {{cmd\|v.voronoi}} and {{cmd\|v.delaunay}})		The next method we will look at is the {{AddonCmd\|r.surf.nnbathy}} add-on module. It performs a {{wikipedia\|natural neighbor}} interpolation. (see also {{cmd\|v.voronoi}} and {{cmd\|v.delaunay}})

	[[Image:Contour1m_surf_NN_nn.png\|thumb\|600px\|center\|r.surf.nnbathy using the default Sibson NN interpolation algorithm]]		[[Image:Contour1m_surf_NN_nn.png\|thumb\|600px\|center\|r.surf.nnbathy using the default Sibson NN interpolation algorithm]]

⚠️Landa: /* r.surf.nnbathy */

2012-12-23T16:49:15Z

r.surf.nnbathy

← Older revision		Revision as of 16:49, 23 December 2012
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	</source>		</source>

	== r.surf.nnbathy ==		== r.surf.nnbathy (addons) ==

	The next method we will look at is the {{AddonCmd\|r.surf.nnbathy}} add-on module. It performs a {{wikipedia\|Natural_neighbor}} interpolation. (see also {{cmd\|v.voronoi}} and {{cmd\|v.delaunay}})		The next method we will look at is the {{AddonCmd\|r.surf.nnbathy}} add-on module. It performs a {{wikipedia\|Natural_neighbor}} interpolation. (see also {{cmd\|v.voronoi}} and {{cmd\|v.delaunay}})

Neteler: + new cat :Category: Interpolation

2010-11-08T07:55:12Z

+ new cat Category: Interpolation

← Older revision		Revision as of 07:55, 8 November 2010
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	[[Category: FAQ]]		[[Category: FAQ]]
			[[Category: Interpolation]]
	[[Category: Documentation]]		[[Category: Documentation]]

⚠️HamishBowman: /* Reference images */ rm pers nnbathy filename

2010-10-09T23:20:52Z

Reference images: rm pers nnbathy filename

← Older revision		Revision as of 23:20, 9 October 2010
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	# nn surfce		# nn surfce
	r.surf.~~nnbathy_17~~ in=elev_lid792_bepts.mean out=elev_lid792_bepts.nn alg=nn		r.surf.nnbathy in=elev_lid792_bepts.mean out=elev_lid792_bepts.nn alg=nn
	r.colors elev_lid792_bepts.nn col=haxby		r.colors elev_lid792_bepts.nn col=haxby
	</source>		</source>

← Older revision		Revision as of 17:59, 31 December 2013
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	[[Category: Interpolation]]		[[Category: Interpolation]]
	[[Category: Documentation]]		[[Category: Documentation]]
			[[Category: Vector]]