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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=string [where=sql_query] [bwidth=integer] [bcolor=string] [legendfile=name] [--overwrite] [--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
--overwrite
Allow output files to overwrite existing files
--verbose
Verbose module output
--quiet
Quiet module output

Parameters:

map=name
Name of vector map
Data source for direct OGR access
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=string
Layer number or name
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
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 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. See the v.class man page for more information on these different algorithms. 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 combined with the -e 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. If the user gives a legendfile, the module will write d.graph instructions for painting a legend into that file.

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 the standard deviation algorithm to calculate class breaks for 5 classes:
d.thematic.area -l map=communes2 data=pop/area algorithm=std nbclasses=5 colors=0:0:255,50:100:255,255:100:50,255:0:0,156:0:0

SEE ALSO

v.class d.vect d.graph v.univar

AUTHOR

Moritz Lennert

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