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

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 (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.

AUTHOR

Wolf Bergenheim

SOURCE CODE

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