1v.colors(1) Grass User's Manual v.colors(1)
2
6 v.colors - Creates/modifies the color table associated with a vector
7 map.
8
10 vector, color table
11
13 v.colors
14 v.colors --help
15 v.colors [-rwlngac] map=name [layer=string] use=string [column=name]
16 [range=min,max] [color=style] [raster=name] [raster_3d=name]
17 [rules=name] [rgb_column=name] [--help] [--verbose] [--quiet]
18 [--ui]
19 Flags:
21 -r
22 Remove existing color table
23 -w
25 Only write new color table if it does not already exist
26 -l
28 List available rules then exit
29 -n
31 Invert colors
32 -g
34 Logarithmic scaling
35 -a
37 Logarithmic-absolute scaling
38 -c
40 Convert color rules from RGB values to color table
41 Option ’rgb_column’ with valid RGB values required
42 --help
44 Print usage summary
45 --verbose
47 Verbose module output
48 --quiet
50 Quiet module output
51 --ui
53 Force launching GUI dialog
54 Parameters:
56 map=name [required]
57 Name of vector map
58 Or data source for direct OGR access
59 layer=string
61 Layer number or name
62 Vector features can have category values in different layers. This
63 number determines which layer to use. When used with direct OGR
64 access this is the layer name.
65 Default: 1
66 use=string [required]
68 Source values
69 Options: attr, cat, z
70 Default: cat
71 attr: read values from attribute table (requires <column> option)
72 cat: use category values
73 z: use z coordinate (3D points or centroids only)
74 column=name
76 Name of column containing numeric data
77 Required for use=attr
78 range=min,max
80 Manually set range (refers to ’column’ option)
81 Ignored when ’rules’ given
82 color=style
84 Name of color table
85 Options: aspect, aspectcolr, bcyr, bgyr, blues, byg, byr, celsius,
86 corine, curvature, differences, elevation, etopo2, evi, fahrenheit,
87 gdd, grass, greens, grey, grey.eq, grey.log, grey1.0, grey255, gyr,
88 haxby, kelvin, ndvi, ndwi, oranges, population, population_dens,
89 precipitation, precipitation_daily, precipitation_monthly, rainbow,
90 ramp, random, reds, roygbiv, rstcurv, ryb, ryg, sepia, slope, soil‐
91 moisture, srtm, srtm_plus, terrain, viridis, water, wave
92 aspect: aspect oriented grey colors
93 aspectcolr: aspect oriented rainbow colors
94 bcyr: blue through cyan through yellow to red
95 bgyr: blue through green through yellow to red
96 blues: white to blue
97 byg: blue through yellow to green
98 byr: blue through yellow to red
99 celsius: blue to red for degree Celsius temperature
100 corine: EU Corine land cover colors
101 curvature: for terrain curvatures (from v.surf.rst and
102 r.slope.aspect)
103 differences: differences oriented colors
104 elevation: maps relative ranges of raster values to elevation
105 color ramp
106 etopo2: colors for ETOPO2 worldwide bathymetry/topography
107 evi: enhanced vegetative index colors
108 fahrenheit: blue to red for Fahrenheit temperature
109 gdd: accumulated growing degree days
110 grass: GRASS GIS green (perceptually uniform)
111 greens: white to green
112 grey: grey scale
113 grey.eq: histogram-equalized grey scale
114 grey.log: histogram logarithmic transformed grey scale
115 grey1.0: grey scale for raster values between 0.0-1.0
116 grey255: grey scale for raster values between 0-255
117 gyr: green through yellow to red
118 haxby: relative colors for bathymetry or topography
119 kelvin: blue to red for temperature in Kelvin scale
120 ndvi: Normalized Difference Vegetation Index colors
121 ndwi: Normalized Difference Water Index colors
122 oranges: white to orange
123 population: color table covering human population classification
124 breaks
125 population_dens: color table covering human population density
126 classification breaks
127 precipitation: precipitation color table (0..2000mm)
128 precipitation_daily: precipitation color table (0..1000mm)
129 precipitation_monthly: precipitation color table (0..1000mm)
130 rainbow: rainbow color table
131 ramp: color ramp
132 random: random color table
133 reds: white to red
134 roygbiv: no description
135 rstcurv: terrain curvature (from r.resamp.rst)
136 ryb: red through yellow to blue
137 ryg: red through yellow to green
138 sepia: yellowish-brown through to white
139 slope: r.slope.aspect-type slope colors for raster values 0-90
140 soilmoisture: soilmoisture color table (0.0-1.0)
141 srtm: color palette for Shuttle Radar Topography Mission elevation
142 srtm_plus: color palette for Shuttle Radar Topography Mission ele‐
143 vation (with seafloor colors)
144 terrain: global elevation color table covering -11000 to +8850m
145 viridis: perceptually uniform sequential color table viridis
146 water: water depth
147 wave: color wave
148 raster=name
150 Raster map from which to copy color table
151 raster_3d=name
153 3D raster map from which to copy color table
154 rules=name
156 Path to rules file
157 rgb_column=name
159 Name of color column to populate RGB values
160 If not given writes color table
161
163 v.colors allows creating or modifying color table associated with a
164 vector map similarly to r.colors for raster maps.
165 Color rules are built from features category values (use=cat) or
167 numeric data column (use=attr) defined by column option. For 3D vector
168 maps is allowed to define color rules based on points or centroids
169 z-coordinate (use=z). 3D vector lines are not supported.
170 The raster option allows user to specify a raster map from which to
172 copy the color table, similarly raster_3d option for 3D raster map.
173 The rules color table type will cause v.colors to read color table
175 specifications from given file and will build the color table accord‐
176 ingly. See r.colors manual page for details.
177 If the user specifies the -w flag, the current color table file for the
179 input map will not be overwritten. This means that the color table is
180 created only if the vector map does not already have a color table. If
181 this option is not specified, the color table will be created if one
182 does not exist, or modified if it does.
183 Alternatively the color rules can be stored in a string column
185 (rgb_column) by saving the RRR:GGG:BBB values suitable for use with
186 d.vect.
187
189 For vector maps with a large number of features it’s more convenient to
190 store color rules in an attribute column (given by rgb_column) rather
191 then in a color table file. Reading color tables with more then 1000
192 items is slow.
193
195 Define color table based on categories
196 Define color table wave based on categories from layer 1
197 v.colors map=soils_general layer=1 color=wave
198 Define color table based on attribute values
200 Define color table ryg based on values from attribute column AREA.
201 Attribute table is linked to layer 1.
202 v.to.db map=soils_general layer=1 option=area column=AREA
203 v.colors map=soils_general layer=1 color=wave use=attr column=AREA
204 Define color table stored as RGB values in attribute table
206 Write color values to the attribute table (column GRASSRGB) instead of
207 creating color table.
208 v.colors map=soils_general layer=1 color=wave use=attr column=AREA rgb_column=GRASSRGB
209 # See some GRASSRGB values:
210 v.db.select map=soils_general where="cat < 4"
211 cat|OBJECTID|AREA|PERIMETER|GSLNC250_|GSLNC250_I|GSL_NAME|GRASSRGB
212 1|1|0|164616.125|2|1|NC113|212:42:127
213 2|2|0|30785.529297|3|2|NC096|212:42:127
214 3|3|0|87572.882812|4|3|NC097|212:42:127
215 Convert RGB attribute values into color table
217 Convert existing RGB values to color table rules.
218 v.colors -c map=soils_general rgb_column=GRASSRGB
219 Note that in this case the vector map has a proper color table assigned
220 (check by v.colors.out) together with GRASSRGB attribute column. Also
221 note that color table is preferred over RGB values stored in attribute
222 table.
223 Remove existing color table
225 Existing color table can be removed by -r flag.
226 v.colors -r map=soils_general
227 Before removing color table you can store color rules to the file by
228 v.colors.out and later to assign by rules option.
229 v.colors.out map=soils_general rules=soils.colr
230 v.colors map=soils_general rules=soils.colr
231 To drop RGB column use v.db.dropcolumn.
232 v.db.dropcolumn map=soils_general column=GRASSRGB
233
235 d.vect, r.colors, r.colors.out, r3.colors, r3.colors.out, v.colors.out
236 See also wiki page Color tables (from GRASS User Wiki)
238 ColorBrewer is an online tool designed to help people select good color
240 schemes for maps and other graphics.
241
243 Martin Landa, OSGeoREL, Czech Technical University in Prague, Czech
244 Republic
245 Last changed: $Date: 2015-02-13 16:14:07 +0100 (Fri, 13 Feb 2015) $
247
249 Available at: v.colors source code (history)
250 Main index | Vector index | Topics index | Keywords index | Graphical
252 index | Full index
253 © 2003-2019 GRASS Development Team, GRASS GIS 7.4.4 Reference Manual
255GRASS 7.4.4 v.colors(1)