Provided by: grass-doc_8.3.0-1_all 
NAME
d.vect.thematic - Displays a thematic vector map in the active graphics frame.
KEYWORDS
display, cartography, choropleth map, legend
SYNOPSIS
d.vect.thematic
d.vect.thematic --help
d.vect.thematic [-lnes] map=name [layer=string] column=name
[breaks=string[,string,...]] [algorithm=string] [nclasses=integer]
colors=string[,string,...] [where=sql_query] [boundary_width=integer]
[boundary_color=name] [icon=string] [size=float] [icon_line=string]
[icon_area=string] [legend_title=string] [legendfile=name] [--overwrite] [--help]
[--verbose] [--quiet] [--ui]
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
DESCRIPTION
d.vect.thematic draws thematic choropleth vector maps based on an attribute column or an
expression involving several columns. It takes a list of class breaks (excluding the
minimum and maximum values) and a list of colors to apply to the classes (has to be the
number of class breaks + 1).
Instead of a list of class breaks, the user can also chose a classification algorithm and
a number of classes (nbclasses). See the v.class for more information on these different
algorithms.
NOTES
The -l flag instructs the module to print legend information in vector legend format as
described in d.legend.vect to standard output for further use in graphical software. When
combined with the verbose flag, the legend information will be extended with some
additional statistical information. If the -n flag is set, the module will only print the
legend information without drawing the map.
Option legendfile, is deprecated, instead use the GRASS_LEGEND_FILE environmental variable
(see d.legend.vect) to save legend into a file. Flag -e is deprecated, instead use
verbose flag.
EXAMPLES
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
SEE ALSO
v.class, d.legend.vect, d.vect, d.graph, v.univar
Check also Python module from AddOns: d.vect.thematic2
AUTHOR
Moritz Lennert
SOURCE CODE
Available at: d.vect.thematic source code (history)
Accessed: Tuesday Jun 27 11:12:36 2023
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