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v.label.sa.1grass

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=integer] column=name 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] [overlap=name] [--verbose] [--quiet]

Parameters:

map=name

Name of input vector map

type=string[,string,...]

Feature type
Options: point,line,area
Default: point,line,area

layer=integer

Layer number
A single vector map can be connected to multiple database tables. This number determines which table to use.
Default: 1

column=name

Name of attribute column to be used for labels

labels=name

Name for new paint-label file

font=string

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

overlap=name

Numeric column to give precedence in case of overlapping labels. The label with a smaller weight is hidden.
Default:

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 rast=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.

SEE ALSO

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

AUTHOR

Wolf Bergenheim

Last changed: $Date: 2009-09-02 23:22:20 +0200 (mer, 02 set 2009) $

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