d.vect.thematic.1grass man page

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 inhab >= 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/arrow1, basic/arrow2, basic/arrow3, basic/box, basic/circle, basic/cross1, basic/cross2, basic/cross3, basic/diamond, basic/marker, basic/octagon, 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/arrow1, basic/arrow2, basic/arrow3, basic/box, basic/circle, basic/cross1, basic/cross2, basic/cross3, basic/diamond, basic/marker, basic/octagon, 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/arrow1, basic/arrow2, basic/arrow3, basic/box, basic/circle, basic/cross1, basic/cross2, basic/cross3, basic/diamond, basic/marker, basic/octagon, 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

Last changed: $Date: 2017-01-05 08:59:34 +0100 (Thu, 05 Jan 2017) $

Source Code

Available at: d.vect.thematic source code (history)

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