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NAME

v.label.sa - Create optimally placed labels for vector map(s)

KEYWORDS

vector, paint labels

SYNOPSIS

v.label.sa
v.label.sa --help
v.label.sa map=name [type=string[,string,...]] [layer=string] column=string labels=name font=string [size=float] [isize=float] [charset=string] [color=string] [hcolor=string] [hwidth=float] [background=string] [opaque=yes|no] [border=string] [width=float] [--help] [--verbose] [--quiet] [--ui]

Flags:

--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
type=string[,string,...]
Input feature type
Options: point, line, area
Default: point,line,area
layer=string
Layer number or name
Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.
Default: 1
column=string [required]
Name of attribute column to be used for labels
labels=name [required]
Name for new paint-label file
font=string [required]
Name of TrueType font (as listed in the fontcap)
size=float
Label size (in map-units)
Default: 100
isize=float
Icon size of point features (in map-units)
Default: 10
charset=string
Character encoding (default: UTF-8)
Default: UTF-8
color=string
Text color
Options: aqua, black, blue, brown, cyan, gray, green, grey, indigo, magenta, orange, purple, red, violet, white, yellow
Default: black
hcolor=string
Highlight color for text
Options: none, aqua, black, blue, brown, cyan, gray, green, grey, indigo, magenta, orange, purple, red, violet, white, yellow
Default: none
hwidth=float
Width of highlight coloring
Default: 0
background=string
Background color
Options: none, aqua, black, blue, brown, cyan, gray, green, grey, indigo, magenta, orange, purple, red, violet, white, yellow
Default: none
opaque=yes|no
Opaque to vector (only relevant if background color is selected)
Options: yes, no
Default: yes
border=string
Border color
Options: none, aqua, black, blue, brown, cyan, gray, green, grey, indigo, magenta, orange, purple, red, violet, white, yellow
Default: none
width=float
Border width (only for ps.map output)
Default: 0

Table of contents

DESCRIPTION

v.label.sa makes a label-file from a GRASS vector map with labels created from attributes in the attached table. The labels are placed in as optimal place as possible. The label file has the same syntax as the one created by v.label

EXAMPLE

North Carolina example: 

# get font names:
d.font -L

v.label.sa roadsmajor labels=roads_labels column=ROAD_NAME color=red \
           background=white size=250 font=Vera

# set region:
g.region raster=lsat7_2002_10 -p

# display:
d.rgb b=lsat7_2002_10 g=lsat7_2002_20 r=lsat7_2002_30
d.vect roadsmajor col=yellow
d.labels roads_labels

Road labeling with v.label.sa
Road labeling with v.label.sa (Raleigh, North Carolina, USA, area)

REFERENCES

Edmondson, Christensen, Marks and Shieber: A General Cartographic Labeling Algorithm, Cartographica, Vol. 33, No. 4, Winter 1996, pp. 13-23 The algorithm works by the principle of Simulated Annealing.

SEE ALSO

d.label
d.labels
ps.map Wikipedia article on simulated annealing

AUTHOR

Wolf Bergenheim

SOURCE CODE

Available at: v.label.sa source code (history)

Accessed: Sunday Jan 22 07:37:03 2023

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