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d.vect.1grass

NAME

d.vect

DESCRIPTION

d.vect displays GRASS vector data in the active frame on the graphics monitor.

NOTES

d.vect can simply be used typing d.vect map=vector_map. There are a large variety of optional parameters which allow the user to specify vector type, colors, data fields, SQL queries, label size and justification, etc.

By default d.vect fills in holes in polygons (islands). If you only want to show active areas limit the features with, e.g., "d.vect cats=1-999999".

In order to display attributes in the map, display=attr must be specified in addition to the column name (attrcol parameter).

Colors may be specified in an attribute table column named 'GRASSRGB' (which is a varchar(11) column containing RRR:GGG:BBB values), see the flag -a.

A table for a vector map might look like this:
echo "select * from testisola" | db.select
cat|label|GRASSRGB
0|no data|255:255:255
90|FRASSILONGO|23:245:67
104|LEVICO|23:145:67
139|PERGINE VALSUGANA|223:45:237
168|SANT'ORSOLA|223:45:67
190|TENNA|123:45:67

To add the GRASSRGB color column, use v.db.addcol:
v.db.addcol testisola col="GRASSRGB varchar(11)"

To add/change a color, use v.db.update:
v.db.update testisola col=GRASSRGB val="123:45:237" where="cat=139"

A much simpler method of color coding is by using the -c flag which displays vector elements of like category number with a random color.

This module can use FreeType/TrueType fonts if they have already been selected with d.font.freetype.

EXAMPLES

Spearfish examples:
# display roads with category numbers:
d.vect roads display=shape,cat lcolor=green

# display randomly colorized soils map with attributes
d.vect -c soils disp=attr attrcol=label

# display randomly colorized selected vectors from soils map
d.vect -c soils where="label='VBF'" display=shape,attr attrcol=label

SEE ALSO

d.erase, d.what.vect, d.rast, d.font.freetype v.db.addcol v.db.update
GRASS SQL interface

AUTHOR

Radim Blazek, ITC-Irst, Trento, Italy

Last changed: $Date: 2007/04/25 20:34:17 $

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