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<em>v.digit</em> is a vector map digitizer with TCL/TK-based graphical
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user interface. Attribute tables can be directly generated while
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digitizing (define in "Settings" first).
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The <b>bgcmd</b> option is intended to be used with display (d.*) commands.
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If several display commands are to be used to render the background
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they should be separated with the semi-colon ';' character.
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When run from the command line, these display commands will generally
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need to be "quoted" as they will contain spaces (see examples).
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<b>Dead (deleted) lines</b>: If a user deletes a line in <em>v.digit</em>,
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it is internally only marked in the geometry file as 'dead' but it remains
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there and occupies space. Any vector module used afterwards on this map
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which really reads and writes vector geometry (so
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not <em><a href="g.copy.html">g.copy</a></em>) will writes only lines
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If <em>v.digit</em> crashes for some reason you can repair the vector map
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which was left open with the <em>v.build</em> module.
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<h3>Start a monitor and display a raster to help setup and zoom to area of interest</h3>
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<div class="code"><pre>
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<h3>Digitizing an area based on a existing raster map; creating a new vector map</h3>
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<div class="code"><pre>
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v.digit -n map=name_of_new_vector_map bgcmd="d.rast map=name_of_raster"
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The <b>-n</b> flag specifies that your vector map does not yet exist and
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thus will be created with the name given by <b>map</b>. The <b>bgcmd</b>
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specifies a display (d.*) command and is set in "quotes" as it contains a space.
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The <em>v.digit</em> GUI appears and vector map "name_of_new_vector_map" is created.
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After leaving <em>v.digit</em>, run:
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<div class="code"><pre>
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d.vect "name_of_new_vector_map"
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The display should be cleared and the newly created vector should appear in
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<h3>Digitizing a second vector, using your first vector and the raster image
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<div class="code"><pre>
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v.digit -n map=name_of_second_vector \
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bgcmd="d.rast map=name_of_your_raster; d.vect map=name_of_new_vector_map"
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The <em>v.digit</em> GUI appears and the layers defined with <b>bgcmd</b>
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are displayed in the background. As the <b>bgcmd</b> commands are executed
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as a series of commands (separated by a ";"), the last command (d.vect)
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displays over the top of the earlier raster image.
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<h3>Combining <b>bgcmd</b> with <em>d.save</em> to use the existing
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display as a backdrop</h3>
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<div class="code"><pre>
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v.digit map=name bgcmd="`d.save -o | cut -f1 -d'#' | tr '\n' ';'`"
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<em><a href="d.save.html"><em>d.save</em></a></em> will list the commands used to draw
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the current display; <em>cut</em> and <em>tr</em> are UNIX commands which are
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used to remove comments and trade newlines for semi-colons, respectively.
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<a href="r.digit.html">r.digit</a>,
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<a href="v.clean.html">v.clean</a>,
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<a href="v.edit.html">v.edit</a>
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See also <em><a href="wxGUI.Vector_Digitizer.html">wxGUI Vector Digitizer</a></em>.
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Radim Blazek, ITC-Irst, Trento, Italy
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<i>Last changed: $Date: 2011-02-01 00:58:25 +0100 (Tue, 01 Feb 2011) $</i>