NAME
v.label - Creates paint labels for a vector map from attached attributes.
KEYWORDS
vector,
paint labels
SYNOPSIS
v.label
v.label --help
v.label [-ac] [labels=name] map=name column=name [type=string[,string,...]] [layer=string] [where=sql_query] [xoffset=float] [yoffset=float] [reference=string[,string,...]] [font=string] [size=float] [space=float] [fontsize=integer] [color=name] [rotation=angle] [width=float] [highlight_color=name] [highlight_width=float] [bgcolor=name] [border=name] [opaque=yes|no] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -a
- Rotate labels to align with lines
- -c
- Curl labels along lines
- --help
- Print usage summary
- --verbose
- Verbose module output
- --quiet
- Quiet module output
- --ui
- Force launching GUI dialog
Parameters:
- labels=name
- Name for new paint-label file
- If not given the name of the input map is used
- map=name [required]
- Name of vector map
- Or data source for direct OGR access
- column=name [required]
- Name of attribute column to be used for labels
- type=string[,string,...]
- Input feature type
- Options: point, line, boundary, centroid
- Default: point,line,boundary,centroid
- 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
- where=sql_query
- WHERE conditions of SQL statement without 'where' keyword
- Example: income < 1000 and population >= 10000
- xoffset=float
- Offset label in x-direction
- Default: 0
- yoffset=float
- Offset label in y-direction
- Default: 0
- reference=string[,string,...]
- Reference position
- Options: center, left, right, upper, lower
- Default: center
- font=string
- Font name
- Default: standard
- size=float
- Label size (in map-units)
- Default: 100
- space=float
- Space between letters for curled labels (in map-units)
- fontsize=integer
- Label size (in points)
- Options: 1-1000
- color=name
- Text color
- Either a standard color name or R:G:B triplet
- Default: black
- rotation=angle
- Rotation angle in degrees (counter-clockwise)
- Options: 0-360
- Default: 0
- width=float
- Border width
- Options: 0-25
- Default: 1
- highlight_color=name
- Highlight color for text
- Either a standard color name, R:G:B triplet, or "none"
- Default: none
- highlight_width=float
- Width of highlight coloring
- Default: 0
- bgcolor=name
- Background color
- Either a standard color name, R:G:B triplet, or "none"
- Default: none
- border=name
- Border color
- Either a standard color name, R:G:B triplet, or "none"
- Default: none
- opaque=yes|no
- Opaque to vector (only relevant if background color is selected)
- Options: yes, no
- Default: yes
v.label makes a label-file from a GRASS vector map
with labels created from attributes in the attached table.
If no label file name is given, the name of the source map is used.
If the
fontsize option is given then the
space option
is determined automatically
from the current display window,
otherwise the
space option should be set roughly the same
as the
size option.
A description of the labels file follows.
The file is located in $MAPSET/paint/labels/
.
The file is a plain-text ASCII file containing the following fields:
Caution: The following information may be incomplete, out of date, and wrong!
The label information that must be provided in the
labels file is:
- TEXT:
-
Lines in multiple line labels will appear one above the next.
More than one line of text can be specified by notating the end of a
line with a '
\n
'.
(e.g. SPEARFISH\nSOUTH DAKOTA)
.
- LOCATION:
- Determines where the text will be located on the
image. The user specifies the easting and northing, and
(optionally) specifies a vertical and horizontal
offset from the specified easting/northing.
These offsets are provided to allow finer placement of labels and
are measured in local pixels. Thus in
d.labels the offset is
measured in screen pixels, and in ps.map
the offset is measured in PostScript points (i.e. 1/72" steps).
- PLACEMENT:
- Determines which part of the label to which the
location refers. If placement is unspecified, the label is
centered (center), by default. Label placement
may be specified as:
lower left (lower left corner of the text)
lower right (lower right corner of the text)
lower center (bottom center of the text)
upper left (upper left corner of the text)
upper right (upper right corner of the text)
upper center (top center of the text)
center (center of the text)
- FONT:
- This specifies the font to use.
The following fonts are available for use with
d.labels:
cyrilc gothgbt gothgrt gothitt greekc greekcs greekp greeks
italicc italiccs italict romanc romancs romand romans romant
scriptc scripts
Alternatively the path to a FreeType (.ttf) font may be given.
(for d.labels only)
The word standard can be used to specify the default font
(which is romans).
Note ps.map can override this setting
to use other fonts. Its default font is Helvetica.
- TEXT SIZE:
- This determines the size of the letters. The size
specifies the vertical height of the letters in meters on
the ground. Thus text will grow or shrink depending on the
scale at which the map is drawn.
Alternatively fontsize can set the font size in normal font points.
- TEXT COLOR:
- This selects the text color. If unspecified, the
label's text is drawn in black, by default. The
text color can be specified in one of several ways:
- By color name:
aqua black blue brown cyan gray green grey indigo
magenta orange purple red violet white yellow
- As red, green, blue component values. (0-255)
for example: 128:100:200
- Specify "
none
" to suppress the lettering.
- WIDTH:
- This determines the line thickness of the border box.
The maximum value is 25.0.
- HIGHLIGHT COLOR:
- The text can be highlighted in another color so that it
appears to be in two colors. The text is drawn first in
this color at a wider line width, and then redrawn in the
text color at the regular line width. No highlight color
("
none
") is used by default, if unspecified by the
user. To specify use of no highlight color, specify
"none
".
(See TEXT COLOR
above for a list of permissible color names.)
- HIGHLIGHT WIDTH:
- Specifies how far from the text lines (in units of
pixels) the highlight color should extend. The default
highlight width is set to 0 (i.e., no highlight
color).
- BACKGROUND COLOR:
- Text may be boxed in a solid color by specifying a background color.
Specify "
none
" for no background. The default background color
setting, if unspecified by the user, is white.
(See TEXT COLOR
above for a list of permissible color names.)
- BORDER COLOR:
- Select a color for the border around the background.
Specify "
none
" to suppress the border.
The default border color used, if unspecified, is black.
(See TEXT COLOR
above for a list of permissible color names.)
- OPAQUE TO VECTORS:
- yes|no. This field only has meaning if a
background color is selected. yes will prevent
vector lines from entering the background. no
will allow vector lines to enter the background. The
default setting, if unspecified by the user, is
yes.
Spearfish example with TrueType font (path may differ):
v.label -a map=roads column=label labels=lroads \
font=/usr/X11R6/lib/X11/fonts/TTF/luximri.ttf
d.vect roads
d.labels lroads
Since the label files are simple text files, you can merge them together
if you like. For example if you set the label colors based on database
attributes using multiple runs with the
where option.
This example uses the standard UNIX
cat
program.
cd $MAPSET/paint/labels/
cat file1 file2 file3 file4 > file_all
d.labels,
ps.map
Philip Verhagen (original s.label)
Radim Blazek (GRASS 6 port)
Hamish Bowman (enhancements)
SOURCE CODE
Available at:
v.label source code
(history)
Latest change: Tuesday Dec 17 20:17:20 2024 in commit: d962e90c026708a4815ea2b9f46c0e84c17de22d
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© 2003-2024
GRASS Development Team,
GRASS GIS 8.4.1dev Reference Manual