NAME

       r.digit   -  Interactive  tool used to draw and save vector features on a graphics monitor
       using a pointing device (mouse) and save to a raster map.

KEYWORDS

       raster, geometry

SYNOPSIS

       r.digit
       r.digit help
       r.digit output=name  [bgcmd=string]   [--overwrite]  [--verbose]  [--quiet]

   Flags:
       --overwrite
           Allow output files to overwrite existing files

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       output=name
           Name for output raster map

       bgcmd=string
           Display commands to be used for canvas backdrop (separated by ';')

DESCRIPTION

       The GRASS tool r.digit provides the user with a way to draw lines, areas, and circles on a
       monitor screen, and to save these features in a raster map.  Lines, areas, and circles are
       to be drawn  using  a  pointing  device  (mouse).   A  mouse  button  menu  indicates  the
       consequences  of  pressing each mouse button.  The user is requested to enter the category
       number associated with the line, area, or circle subsequently drawn by the  user.   Lines,
       areas,  and  circles are defined by the series of points marked by the user inside the map
       window.  r.digit will close areas when the user has not.  By  drawing  a  series  of  such
       features,  the  user  can repair maps, identify areas of interest, or simply draw graphics
       for advertisement.   When  drawing  is  completed,  a  raster  map  based  on  the  user's
       instructions  is  generated.   It  is  available  for  use as a mask, in analyses, and for
       display.

       The bgcmd option is intended to be used with display (d.*) commands.  If  several  display
       commands  are  to be used to render the background they should be separated with the semi-
       colon ';' character.  When  run  from  the  command  line,  these  display  commands  will
       generally need to be "quoted" as they will contain spaces (see examples).

       Digitizing  is done in a "polygon" method.  Each area is circumscribed completely.  Two or
       more overlapping areas and/or lines might define a single part of a map.  Each part of the
       map, however, is assigned only the LAST area or line which covered it.

   THE PROCESS:
   Start a monitor and display a raster to help setup and zoom to area of interest

       d.mon x0

   Digitizing an area based on a existing map; creating a new raster map

       r.digit out=name_of_new_raster_map bgcmd="d.rast map=name_of_raster"

       1      Choose  to define an area or line, exit, or quit.  If you choose to finish (exit) a
              new map is then created.  If you quit, the session exits with nothing created.

       2      If you choose to make an area or line you must identify  the  category  number  for
              that area or line.

       3      Using the mouse trace the line or circumscribe the area; or, finish (go to Step 1).

SEE ALSO

       v.digit, d.graph, d.linegraph, g.region, r.in.poly, r.mapcalc, r.to.vect, v.in.ascii

AUTHOR

       Michael Shapiro, U.S.Army Construction Engineering Research Laboratory

       Last changed: $Date: 2008-05-16 12:09:06 -0700 (Fri, 16 May 2008) $

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