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NAME

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

KEYWORDS

display

SYNOPSIS

d.thematic.area
d.thematic.area help
d.thematic.area [-lnx] map=name column=string breaks=string[,string,...] colors=string[,string,...] [layer=integer] [where=sql_query] [bwidth=integer] [bcolor=string] [render=string] [--verbose] [--quiet]

Flags:

-l
Create legend information and send to stdout
-n
Do not draw map, only output the legend
-x
Don't add to list of vectors and commands in monitor (it won't be drawn if the monitor is refreshed)
--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
colors=string[,string,...]
Colors (one more than class breaks).
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: g,r,d,c,l
Default: l
g: use the libgis render functions (features: clipping)
r: use the raster graphics library functions (features: polylines)
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)

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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© 2003-2008 GRASS Development Team