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NAME

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

KEYWORDS

display

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 < 1000 and inhab >= 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

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