---
name: "d.thematic.area"
section: "1grass"
platform: "linux"
package: "grass-doc"
version: "6.4.4-1"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/d.thematic.area"
---

# d.thematic.area(1grass)

Displays a thematic vector area map in the active frame on the graphics monitor.

## NAME

**d.thematic.area**  - Displays a thematic vector area map in the active frame on the graphics monitor.

## KEYWORDS

display, cartography

## SYNOPSIS

**d.thematic.area**\
 **d.thematic.area help**\
 **d.thematic.area** \[-**len**\] **map**=*name* **column**=*string*  \[**breaks**=*string*\[,*string*,...\]\]   \[**algorithm**=*string*\]   \[**nbclasses**=*integer*\]  **colors**=*string*\[,*string*,...\]  \[**layer**=*integer*\]   \[**where**=*sql\_query*\]   \[**bwidth**=*integer*\]   \[**bcolor**=*string*\]   \[**render**=*string*\]   \[**legendfile**=*name*\]   \[--**verbose**\]  \[--**quiet**\]

### Flags:

- **-l**

  Create legend information and send to stdout

- **-e**

  When printing legend info , include extended statistical info from classification algorithm

- **-n**

  Do not draw map, only output the legend

- **--verbose**

  Verbose module output

- **--quiet**

  Quiet module output

### Parameters:

- **map**=*name*

  Name of input vector map

- **column**=*string*

  Data to be classified: column name or expression

- **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)

- **nbclasses**=*integer*

  Number of classes to define

- **colors**=*string\[,string*,...\]

  Colors (one per class).

- **layer**=*integer*

  Layer number\
   Layer number. If -1, all layers are displayed.\
   Default: *1*

- **where**=*sql\_query*

  WHERE conditions of SQL statement without 'where' keyword\
   Example: income = 10000

- **bwidth**=*integer*

  Boundary width\
   Default: *0*

- **bcolor**=*string*

  Boundary color\
   Default: *black*

- **render**=*string*

  Rendering method for filled polygons\
   Options: *d,c,l*\
   Default: *l*\
   **d**: use the display library basic functions (features: polylines)\
   **c**: use the display library clipping functions (features: clipping)\
   **l**: use the display library culling functions (features: culling, polylines)

- **legendfile**=*name*

  File in which to save d.graph instructions for legend display

## DESCRIPTION

*d.thematic.area* draws thematic coropleth vector maps based on an attribute column or an expression involving several columns. It takes a number 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). The *-l* flag instructs the module to print legend information (class min \| class max \| number of observations in class \| color) to standard output for futher use in graphical software. When given this flag with the *-n* flag, the module will only print the legend information without drawing the map. One can used *v.class* to supply class breaks for d.thematic.area (see example below);

## EXAMPLE

`d.thematic.area -l map=communes3 data=pop breaks=111393.250000,222785.500000,334177.750000 colors=255:0:0,0:255:0,0:0:255,0,0,0`\
 The following example uses a calculated attribute (density = pop/area) and v.class to calculate class breaks and feed them directly into d.thematic.area:\
 ``d.thematic.area -l map=communes2 data=pop/area breaks=`v.class -g map=communes2 column=pop/area algo=std nbcla=5` colors=0:0:255,50:100:255,255:100:50,255:0:0,156:0:0``\

## SEE ALSO

*v.class* *d.vect* *v.univar*

## AUTHOR

Moritz Lennert

Full index

© 2003-2014 GRASS Development Team