NAME

v.digit - A menu-driven, highly interactive map development program used for vector digitizing, editing, labeling and converting vector data to raster format.
(GRASS Vector Program)

SYNOPSIS

v.digit

DESCRIPTION

The GRASS program v.digit is a menu-driven, highly interactive map development program used for inputting analog map data into a GRASS vector format. v.digit contains programs for vector digitizing, editing, labeling, windowing, and converting vector data to GRASS raster format.

v.digit consists of two parts: an initialization procedure, and a multiple menu-driven environment.

  1. The initialization procedure involves choosing a digitizer, choosing the name of a vector map layer to digitize, and, if needed, registering a map to the digitizing surface. It is important to specify the map scale.
  2. The second part of v.digit is a multiple-menu environment in which digitizing, editing, labeling, and other options are available. It is within this second portion of v.digit that all vector creation occurs.

NOTES

v.digit was written to optimize digitizing speed and performance. It has a convenient graphic display format and very convenient windowing capabilities. Features are color-coded for ease of identification and verification. Different color schemes may be user-chosen to customize a digitizing session.

Area, line, and point features may be digitized in both "stream" and "point" modes. Both a mouse and a digitizer may be used to perform windowing functions. Labeling and editing are done from within v.digit, rather than through a separate set of programs.

v.digit has capabilities that allow users to display raster maps in background (Customize menu, Backdrop), to overlay already existing vector map layers onto the feature being digitized (Customize menu, Overlay), and set a multitude of parameters to furtherly customize a digitizing session.

v.digit may be used with or without a digitizer. Many options are available if no digitizer is used, i.e. digitizer support by mouse.

All options available within v.digit are contained within ten menus. Movement from menu to menu is done by chosing the movement options specified at the bottom of each menu.

Digitizer support

GRASS is using device independent code written originally by John Dabritz formerly of the Forest Service, which uses ascii description files to define how to communicate with the digitizer. The result is that we should be able to support just about any digitizer out there now with a minimum of work. Refer to the "digitizer definition manual" for information on the format of these files.

SEE ALSO

GRASS 4.0 map digitizing manual: v.digit

v.import, v.in.ascii, v.out.ascii, v.spag, v.out.rast, v.trim, v.support

AUTHORS

David Gerdes,
Mike Higgins,
U.S. Army Construction Engineering Research Laboratory
Improvements by Huidae Cho