v.colors - Creates/modifies the color table
associated with a vector map.
v.colors
v.colors --help
v.colors [-rwldngac] map=name
[layer=string] use=string
[column=name] [range=min,max]
[color=style] [raster=name]
[raster_3d=name] [rules=name]
[rgb_column=name] [--help] [--verbose]
[--quiet] [--ui]
- -r
-
Remove existing color table
- -w
-
Only write new color table if it does not already exist
- -l
-
List available rules then exit
- -d
-
List available rules with description then exit
If a color rule is given, only this rule is listed
- -n
-
Invert colors
- -g
-
Logarithmic scaling
- -a
-
Logarithmic-absolute scaling
- -c
-
Convert color rules from RGB values to color table
Option ’rgb_column’ with valid RGB values required
- --help
-
Print usage summary
- --verbose
-
Verbose module output
- --quiet
-
Quiet module output
- --ui
-
Force launching GUI dialog
- map=name
[required]
-
Name of vector map
Or data source for direct OGR access
- layer=string
-
Layer number or name
Vector features can have category values in different layers. This number
determines which layer to use. When used with direct OGR access this is
the layer name.
Default: 1
- use=string
[required]
-
Source values
Options: attr, cat, z
Default: cat
attr: read values from attribute table (requires <column>
option)
cat: use category values
z: use z coordinate (3D points or centroids only)
- column=name
-
Name of column containing numeric data
Required for use=attr
- range=min,max
-
Manually set range (refers to ’column’ option)
Ignored when ’rules’ given
- color=style
-
Name of color table
Options: aspect, aspectcolr, bcyr, bgyr, blues, byg, byr, celsius,
corine, curvature, differences, elevation, etopo2, evi, fahrenheit, gdd,
grass, greens, grey, grey.eq, grey.log, grey1.0, grey255, gyr, haxby,
inferno, kelvin, magma, ndvi, ndwi, oranges, plasma, population,
population_dens, precipitation, precipitation_daily,
precipitation_monthly, rainbow, ramp, random, reds, roygbiv, rstcurv, ryb,
ryg, sepia, slope, soilmoisture, srtm, srtm_plus, terrain, viridis, water,
wave
aspect: aspect oriented grey colors [range: map values]
aspectcolr: aspect oriented rainbow colors [range: 0 to 360]
bcyr: blue through cyan through yellow to red [range: map values]
bgyr: blue through green through yellow to red [range: map values]
blues: white to blue [range: map values]
byg: blue through yellow to green [range: map values]
byr: blue through yellow to red [range: map values]
celsius: blue to red for degree Celsius temperature [range: -80 to
80]
corine: EU Corine land cover colors [range: 111 to 995]
curvature: for terrain curvatures (from v.surf.rst and
r.slope.aspect) [range: map values]
differences: differences oriented colors [range: map values]
elevation: maps relative ranges of raster values to elevation color
ramp [range: map values]
etopo2: colors for ETOPO2 worldwide bathymetry/topography [range:
-11000 to 8850]
evi: enhanced vegetative index colors [range: -1 to 1]
fahrenheit: blue to red for Fahrenheit temperature [range: -112 to
176]
gdd: accumulated growing degree days [range: 0 to 6000]
grass: GRASS GIS green (perceptually uniform) [range: map values]
greens: white to green [range: map values]
grey: grey scale [range: map values]
grey.eq: histogram-equalized grey scale [range: map values]
grey.log: histogram logarithmic transformed grey scale [range: map
values]
grey1.0: grey scale for raster values between 0.0-1.0 [range: 0 to
1]
grey255: grey scale for raster values between 0-255 [range: 0 to
255]
gyr: green through yellow to red [range: map values]
haxby: relative colors for bathymetry or topography [range: map
values]
inferno: perceptually uniform sequential color table inferno [range:
map values]
kelvin: blue to red for temperature in Kelvin scale [range: 193.15
to 353.15]
magma: perceptually uniform sequential color table magma [range: map
values]
ndvi: Normalized Difference Vegetation Index colors [range: -1 to 1]
ndwi: Normalized Difference Water Index colors [range: -200 to 200]
oranges: white to orange [range: map values]
plasma: perceptually uniform sequential color table plasma [range:
map values]
population: color table covering human population classification
breaks [range: 0 to 2e+09]
population_dens: color table covering human population density
classification breaks [range: 0 to 1e+09]
precipitation: precipitation color table (0..2000mm) [range: 0 to
7000]
precipitation_daily: precipitation color table (0..1000mm) [range: 0
to 10000]
precipitation_monthly: precipitation color table (0..1000mm) [range:
0 to 1000]
rainbow: rainbow color table [range: map values]
ramp: color ramp [range: map values]
random: random color table [range: map values]
reds: white to red [range: map values]
roygbiv: [range: map values]
rstcurv: terrain curvature (from r.resamp.rst) [range: map values]
ryb: red through yellow to blue [range: map values]
ryg: red through yellow to green [range: map values]
sepia: yellowish-brown through to white [range: map values]
slope: r.slope.aspect-type slope colors for raster values 0-90
[range: 0 to 90]
soilmoisture: soilmoisture color table (0.0-1.0) [range: 0 to 1]
srtm: color palette for Shuttle Radar Topography Mission elevation
[range: -11000 to 8850]
srtm_plus: color palette for Shuttle Radar Topography Mission
elevation (with seafloor colors) [range: -11000 to 8850]
terrain: global elevation color table covering -11000 to +8850m
[range: -11000 to 8850]
viridis: perceptually uniform sequential color table viridis [range:
map values]
water: water depth [range: map values]
wave: color wave [range: map values]
- raster=name
-
Raster map from which to copy color table
- raster_3d=name
-
3D raster map from which to copy color table
- rules=name
-
Path to rules file
- rgb_column=name
-
Name of color column to populate RGB values
If not given writes color table
v.colors allows creating or modifying color table
associated with a vector map similarly to r.colors for raster
maps.
Color rules are built from features category values
(use=cat) or numeric data column (use=attr) defined by
column option. For 3D vector maps is allowed to define color rules
based on points or centroids z-coordinate (use=z). 3D vector lines
are not supported.
The raster option allows user to specify a raster map from
which to copy the color table, similarly raster_3d option for 3D
raster map.
The rules color table type will cause v.colors to
read color table specifications from given file and will build the color
table accordingly. See r.colors manual page for details.
If the user specifies the -w flag, the current color table
file for the input map will not be overwritten. This means that the color
table is created only if the vector map does not already have a color table.
If this option is not specified, the color table will be created if one does
not exist, or modified if it does.
Alternatively the color rules can be stored in a string column
(rgb_column) by saving the RRR:GGG:BBB values suitable for use with
d.vect.
For vector maps with a large number of features it’s more
convenient to store color rules in an attribute column (given by
rgb_column) rather then in a color table file. Reading color tables
with more then 1000 items is slow.
Define color table wave based on categories from layer 1
v.colors map=soils_general layer=1 color=wave
Define color table ryg based on values from attribute column AREA.
Attribute table is linked to layer 1.
v.to.db map=soils_general layer=1 option=area column=AREA
v.colors map=soils_general layer=1 color=wave use=attr column=AREA
Write color values to the attribute table (column GRASSRGB)
instead of creating color table.
v.colors map=soils_general layer=1 color=wave use=attr column=AREA rgb_column=GRASSRGB
# See some GRASSRGB values:
v.db.select map=soils_general where="cat < 4"
cat|OBJECTID|AREA|PERIMETER|GSLNC250_|GSLNC250_I|GSL_NAME|GRASSRGB
1|1|0|164616.125|2|1|NC113|212:42:127
2|2|0|30785.529297|3|2|NC096|212:42:127
3|3|0|87572.882812|4|3|NC097|212:42:127
Convert existing RGB values to color table rules.
v.colors -c map=soils_general rgb_column=GRASSRGB
Note that in this case the vector map has a proper color table
assigned (check by v.colors.out) together with GRASSRGB attribute
column. Also note that color table is preferred over RGB values stored in
attribute table.
Existing color table can be removed by -r flag.
v.colors -r map=soils_general
Before removing color table you can store color rules to the file
by v.colors.out and later to assign by rules option.
v.colors.out map=soils_general rules=soils.colr
v.colors map=soils_general rules=soils.colr
To drop RGB column use v.db.dropcolumn.
v.db.dropcolumn map=soils_general column=GRASSRGB
d.vect, r.colors, r.colors.out,
r3.colors, r3.colors.out, v.colors.out
See also wiki page Color tables (from GRASS User Wiki)
ColorBrewer is an online tool designed to help people select good
color schemes for maps and other graphics.
Martin Landa, OSGeoREL, Czech Technical University in Prague,
Czech Republic
Last changed: $Date: 2015-02-13 16:14:07 +0100 (Fri, 13 Feb
2015) $
Available at: v.colors source code (history)
Main index | Vector index | Topics index | Keywords index |
Graphical index | Full index
© 2003-2019 GRASS Development Team, GRASS GIS 7.6.0
Reference Manual