Flags:¶

-l

Create legend information and send to stdout

-n

Do not draw map, only output the legend information

-e

[DEPRECATED] When printing legend info, include extended statistical info from classification algorithm

-s

Do not show this layer in vector legend

--overwrite

Allow output files to overwrite existing files

--help

Print usage summary

--verbose

Verbose module output

--quiet

Quiet module output

--ui

Force launching GUI dialog

Parameters:¶

map=name [required]

Name of vector map
Or data source for direct OGR access

layer=string

Layer number or name
Layer number. If -1, all layers are displayed.
Default: 1

column=name [required]

Name of attribute column to be classified

breaks=string[,string,...]

Class breaks, without minimum and maximum

algorithm=string

Algorithm to use for classification
Options: int, std, qua, equ, dis
int: simple intervals
std: standard deviations
qua: quantiles
equ: equiprobable (normal distribution)

nclasses=integer

Number of classes to define

colors=string[,string,...] [required]

Colors (one per class)

where=sql_query

WHERE conditions of SQL statement without ’where’ keyword
Example: income < 1000 and population >= 10000

boundary_width=integer

Boundary width
Default: 1

boundary_color=name

Boundary color
Either a standard color name, R:G:B triplet, or "none"
Default: black

icon=string

Point and centroid symbol
Options: basic/arrow, basic/arrow1, basic/arrow2, basic/arrow3, basic/box, basic/circle, basic/cross1, basic/cross2, basic/cross3, basic/diamond, basic/hexagon, basic/marker, basic/octagon, basic/pin, basic/pin_dot, basic/point, basic/pushpin, basic/star, basic/triangle, basic/x, demo/muchomurka, demo/smrk, extra/4pt_star, extra/adcp, extra/airport, extra/alpha_flag, extra/bridge, extra/dim_arrow, extra/dive_flag, extra/fiducial, extra/fish, extra/half-box, extra/half-circle, extra/offbox_ne, extra/offbox_nw, extra/offbox_se, extra/offbox_sw, extra/pentagon, extra/ping, extra/ring, extra/simple_zia, extra/target, geology/circle_cross, geology/half-arrow_left, geology/half-arrow_right, geology/strike_box, geology/strike_circle, geology/strike_cleavage, geology/strike_half-bowtie, geology/strike_line, geology/strike_parallel, geology/strike_triangle, legend/area, legend/area_curved, legend/line, legend/line_crooked, n_arrows/basic_compass, n_arrows/fancy_compass, n_arrows/n_arrow1a, n_arrows/n_arrow1b, n_arrows/n_arrow2, n_arrows/n_arrow3, n_arrows/n_arrow4, n_arrows/n_arrow5, n_arrows/n_arrow6, n_arrows/n_arrow7a, n_arrows/n_arrow7b, n_arrows/n_arrow8a, n_arrows/n_arrow8b, n_arrows/n_arrow9
Default: basic/x

size=float

Symbol size
Default: 5

icon_line=string

Legend symbol for lines
Options: basic/arrow, basic/arrow1, basic/arrow2, basic/arrow3, basic/box, basic/circle, basic/cross1, basic/cross2, basic/cross3, basic/diamond, basic/hexagon, basic/marker, basic/octagon, basic/pin, basic/pin_dot, basic/point, basic/pushpin, basic/star, basic/triangle, basic/x, demo/muchomurka, demo/smrk, extra/4pt_star, extra/adcp, extra/airport, extra/alpha_flag, extra/bridge, extra/dim_arrow, extra/dive_flag, extra/fiducial, extra/fish, extra/half-box, extra/half-circle, extra/offbox_ne, extra/offbox_nw, extra/offbox_se, extra/offbox_sw, extra/pentagon, extra/ping, extra/ring, extra/simple_zia, extra/target, geology/circle_cross, geology/half-arrow_left, geology/half-arrow_right, geology/strike_box, geology/strike_circle, geology/strike_cleavage, geology/strike_half-bowtie, geology/strike_line, geology/strike_parallel, geology/strike_triangle, legend/area, legend/area_curved, legend/line, legend/line_crooked, n_arrows/basic_compass, n_arrows/fancy_compass, n_arrows/n_arrow1a, n_arrows/n_arrow1b, n_arrows/n_arrow2, n_arrows/n_arrow3, n_arrows/n_arrow4, n_arrows/n_arrow5, n_arrows/n_arrow6, n_arrows/n_arrow7a, n_arrows/n_arrow7b, n_arrows/n_arrow8a, n_arrows/n_arrow8b, n_arrows/n_arrow9
Default: legend/line

icon_area=string

Legend symbol for areas
Options: basic/arrow, basic/arrow1, basic/arrow2, basic/arrow3, basic/box, basic/circle, basic/cross1, basic/cross2, basic/cross3, basic/diamond, basic/hexagon, basic/marker, basic/octagon, basic/pin, basic/pin_dot, basic/point, basic/pushpin, basic/star, basic/triangle, basic/x, demo/muchomurka, demo/smrk, extra/4pt_star, extra/adcp, extra/airport, extra/alpha_flag, extra/bridge, extra/dim_arrow, extra/dive_flag, extra/fiducial, extra/fish, extra/half-box, extra/half-circle, extra/offbox_ne, extra/offbox_nw, extra/offbox_se, extra/offbox_sw, extra/pentagon, extra/ping, extra/ring, extra/simple_zia, extra/target, geology/circle_cross, geology/half-arrow_left, geology/half-arrow_right, geology/strike_box, geology/strike_circle, geology/strike_cleavage, geology/strike_half-bowtie, geology/strike_line, geology/strike_parallel, geology/strike_triangle, legend/area, legend/area_curved, legend/line, legend/line_crooked, n_arrows/basic_compass, n_arrows/fancy_compass, n_arrows/n_arrow1a, n_arrows/n_arrow1b, n_arrows/n_arrow2, n_arrows/n_arrow3, n_arrows/n_arrow4, n_arrows/n_arrow5, n_arrows/n_arrow6, n_arrows/n_arrow7a, n_arrows/n_arrow7b, n_arrows/n_arrow8a, n_arrows/n_arrow8b, n_arrows/n_arrow9
Default: legend/area

legend_title=string

Thematic map title

legendfile=name

[DEPRECATED] Output legend file

Thematic map with classes¶

d.vect.thematic -l map=communes3 column=pop \


  breaks=111393.250000,222785.500000,334177.750000 \


  colors="255:0:0,0:255:0,0:0:255,0,0,0"

Thematic map with calculated class breaks¶

The following example uses a calculated attribute (density = pop/area) and the standard deviation algorithm to calculate class breaks for 5 classes:

d.vect.thematic -l map=communes2 column=pop/area algorithm=std \


  nbclasses=5 colors="0:0:255,50:100:255,255:100:50,255:0:0,156:0:0"

Thematic map with legend¶

Example for the North Carolina sample dataset, colorizing basin polygons by average elevation and displaying school capacity:

# create watersheds from elevation map
g.region raster=elevation
r.watershed elevation=elevation threshold=10000 basin=basins_10k
# convert raster to vector
r.to.vect input=basins_10k output=basins_10k type=area column=basin_num
# upload raster statistics to each polygon in vector map
v.rast.stats map=basins_10k raster=elevation column_prefix=elev
# open a graphical display
d.mon wx0
# draw thematic polygons and specify legend title
d.vect.thematic map=basins_10k column=elev_average algorithm=int \


  nclasses=5 colors=0:195:176,39:255:0,251:253:0,242:127:11,193:126:60 \


  legend_title="Average elevation (m)"
# draw thematic points and specify legend title
d.vect.thematic map=schools_wake@PERMANENT column=CORECAPACI algorithm=std \


  nclasses=3 colors=149:203:255,45:143:240,0:81:161 icon=basic/circle size=15 \


  legend_title="School capacity"
# and finally draw legend
d.legend.vect -b at=2,80 font=Sans symbol_size=25

Thematic map of average elevation and school capacity