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NAME
r.profile - Outputs the raster map layer values lying on user-defined line(s).
KEYWORDS
raster
SYNOPSIS
r.profile
r.profile help
r.profile [-gc] input=name [output=string] [profile=east,north[,east,north,...]] [res=float] [null=string] [--verbose] [--quiet]
Flags:
- -g
- Output easting and northing in first two columns of four column output
- -c
- Output RRR:GGG:BBB color values for each profile point
- --verbose
- Verbose module output
- --quiet
- Quiet module output
Parameters:
- input=name
- Name of input raster map
- output=string
- Name of file for output (use output=- for stdout)
- Default: -
- profile=east,north[,east,north,...]
- Profile coordinate pairs
- res=float
- Resolution along profile (default = current region resolution)
- null=string
- Character to represent no data cell
- Default: *
DESCRIPTION
This program outputs two or four column (with -g) data to stdout or
an ASCII file. The default two column output consists of cumulative profile
length (in meters) and raster value. The optional four column output consists
of easting, northing, cumlative profile length (m), and raster value. Profile
end or "turning" points can be set manually with the profile
argument or selected interactively from the GRASS monitor by setting the
-i flag. The profile resolution, or distance between profile
points, is obtained from the current region resolution, or can be manually
set with the res argument.
The -i flag allows the user for selecting the profile from the GRASS
monitor by clicking the left mouse button along the profile; clicking the
right mouse button ends the profile.
The profile parameter can be set to comma separated geographic
coordinates for profile line endpoints. The interactive flag (-i)
overrides this option. Alternatively the coordinate pairs can be piped
from stdin, one comma separated pair per line.
The res parameter sets the distance between each profile point
(resolution). The resolution must be provided in GRASS database units (i.e.
decimal degrees for Lat Long databases and meters for UTM). By default
r.profile uses the resolution of the current GRASS region.
The null parameter can optionally be set to change the character
string representing null values.
OUTPUT FORMAT
The multi column output from r.profile is intended for easy use in
other programs. The output can be piped (|) directly into other programs or
saved to a file for later use. Output with geographic coordinates (-g)
is compatible with v.in.ascii and can
be piped direcly into this program.
r.profile -ig input=elev.rast | v.in.ascii output=elev.profile fs=space
The 2 column output is compatible with most plotting programs.
The optional RGB output provides the associated GRASS colour value for
each profile point.
EXAMPLES
Example 1
Extract a profile with coordinates provided on the command line:
r.profile input=elev.rast output=profile.pts profile=562517,7779433,562984,7779533,563875,7779800
This will extract a profile along the track defined by the three coordinate
pairs.
Example 2
Extract a profile by interactively selecting the profile route from the GRASS
monitor:
r.profile -i input=elev.rast output=profile.pts
Use the left mouse button to select the profile route in the GRASS monitor. Use the
right mouse button to end the profile.
Example 3
Extract a profile with coordinates provided from standard input or an external file:
First create a points file with d.where
Then pipe the points file into r.profile
cat saved.points | r.profile input=elev.rast output=profile.pts
The advantage of this method is that the same profile points can be piped into
different GRASS rasters by changing the input parameter.
With this method the coordinates must be given as space or tab separated easting
and northing. Labels after these values are ignored.
Another example using d.where:
d.where | r.profile elevation.dem
Example 4
Pipe coordinates into r.profile
r.profile elevation.dem res=1000 << EOF
591243,4926344
592509,4922156
594100,4920793
599910,4919365
602929,4919235
604844,4918391
606468,4917190
607766,4915664
EOF
NOTES
The profile resolution is measured exactly from the supplied end or
"turning" point along the profile. The end of a profile segment will be an
exact multiple of the profile resolution and will therefore not always match
the end point coordinates entered for the segmanet.
To extract the numbers in scripts, following parameters can be used:
r.profile input=dgm12.5 profile=3570631,5763556 2>/dev/null
This filters out the everything except the numbers.
SEE ALSO
v.in.ascii,
d.where,
d.profile,
r.what,
r.transect,
gis.m: PROFILE TOOL
AUTHOR
Bob Covill
Last changed: $Date: 2010-01-15 00:14:33 -0800 (Fri, 15 Jan 2010) $
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