## NAME

d.area - Draws labelled vector lines to the GRASS display
(GRASS Display/Vector Program)

## SYNOPSIS

d.vect.line map=name [color=name|R:G:B] [catnum=i[,j,k,...,n]] [legend=filename|"-"]

### Parameters:

map
  Name of existing vector map to be displayed
color
  Color desired for drawing lines. May be specified as a standard grass color name, or as an RGB triplet (e.g. 80:198:255).
  Default: white
catnum
  List of category numbers to restrict which lines are drawn. Ignored if the legend option is used.
legend
  Name of a legend file specifying what color to use for each category (see below). If "-" is specified, the legend will be read from standard input.
  Default: none

## DESCRIPTION

Use d.vect.line to draw labelled lines from a vector map to the GRASS display. By default, d.vect.line will draw all labelled lines in the vector map with white. The lines drawn may be restricted via the catnum argument or by using a legend file.

The color argument may be any of the standard named GRASS colors, or and RGB (red, green, blue) triplet. An RGB triplet must have the form <num>:<num>:<num> where num is between 0 and 255.

An optional list of category numbers may be used to restrict which lines are drawn (option ignored if a legend option is given).

More control can be had by creating a legend file. At the time of this writing, GRASS does not have any management functions for specifying how vectors should be drawn, so this file must be created by "hand". The easiest way to create such a file, is to copy the category file for the vector map, and edit it to contain color specifications. The format of the legend file is category red green blue, with one entry per line. If a category for a map is not included in this file, it will not be drawn unless there is a special "default" entry with a category of -1.

Example Legend File
  -1 255 255 255
  1 210 198 168
  5 168 198 220

In the above, all labelled lines will be drawn in white (255, 255, 255) except those labelled as categories 1 or 5. If the "default" entry had been omitted, then only lines labelled 1 or 5 would have been drawn.

One may place comments on any line in the legend file by starting it with a non-numeric character ('#' is a good choice). Empty lines are ignored.

## NOTES

It is expected that the legend specification aspect of this module will change when an infrastructure for managing vector drawing styles is implemented.

## AUTHOR

Eric G. Miller

Last changed: $Date: 2002/02/06 06:19:26 $