d.vect.thematic - Displays a thematic vector map in the active graphics frame.

Author

       Moritz Lennert

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.

Examples

Thematicmapwithclasses
       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"

   Thematicmapwithcalculatedclassbreaks
       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"

   Thematicmapwithlegend
       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
       Thematicmapofaverageelevationandschoolcapacity

Keywords

       display, cartography, choropleth map, legend

Name

d.vect.thematic  - Displays a thematic vector map in the active graphics frame.

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.

Source Code

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

       Accessed: Friday Apr 04 01:18:52 2025

       Main index | Display index | Topics index | Keywords index | Graphical index | Full index

       © 2003-2025 GRASS Development Team, GRASS GIS 8.4.1 Reference Manual

GRASS 8.4.1                                                                              d.vect.thematic(1grass)

Synopsis

d.vect.thematicd.vect.thematic--helpd.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: 1column=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,disint: 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: 1boundary_color=name
           Boundary color
           Either a standard color name, R:G:B triplet, or "none"
           Default: blackicon=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/xsize=float
           Symbol size
           Default: 5icon_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/lineicon_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/arealegend_title=string
           Thematic map title

       legendfile=name
           [DEPRECATED] Output legend file