NAME
r.contour - Produces a vector map layer of specified contours from a raster map layer.
KEYWORDS
raster
SYNOPSIS
r.contour
r.contour help
r.contour [-qn] input=name output=name [levels=float[,float,...]] [minlevel=float] [maxlevel=float] [step=float] [cut=integer] [--overwrite] [--verbose] [--quiet]
Flags:
- -q
- Run quietly
- -n
- Suppress single crossing error messages
- --overwrite
- Allow output files to overwrite existing files
- --verbose
- Verbose module output
- --quiet
- Quiet module output
Parameters:
- input=name
- Name of input raster map
- output=name
- Name for output vector map
- levels=float[,float,...]
- List of contour levels
- minlevel=float
- Minimum contour level
- maxlevel=float
- Maximum contour level
- step=float
- Increment between contour levels
- cut=integer
- Minimum number of points for a contour line (0 -> no limit)
- Default: 0
DESCRIPTION
r.contour produces a GRASS binary vector map of specified contours from GRASS raster map layer.
- Contours are produced from a user-specified list of levels.
-
Contours are produced at some regular increment from user-specified minimum
level to maximum level. If no minimum or maximum level is specified, minimum
or maximum data value will be used.
NOTES
r.contour will either step through incremental contours or produce
contours from a list of levels, not both. If both a list of levels and
a step are specified, the list will be produced and the step will be ignored.
Zero is treated as a valid data value by r.contour.
If a contour level exactly matches a category value in the raster map,
the contour line may backtrack on itself, causing illegal arcs to be produced
in the output GRASS vector map.
The optional cut parameter allows to specify a minimum number of
point for a contour line to be put into output vector map, so that small
spurs, single points and so on won't be present and the output will be more
clear.
AUTHORS
Terry Baker, U.S. Army Construction Engineering Research Laboratory
3/2001: cut parameter and fixes by Andrea Aime ([email protected])
Last changed: $Date: 2006-12-13 08:10:28 -0800 (Wed, 13 Dec 2006) $
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