1wxGUI.rdigit(1)             GRASS GIS User's Manual            wxGUI.rdigit(1)
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wxGUI Raster Digitizer

KEYWORDS

7       display, GUI, raster, editing, digitizer
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DESCRIPTION

10       Raster  Digitizer is a simple tool to quickly to draw lines, areas, and
11       circles and save these features in a raster map.  It is accessible from
12       Map Display toolbar (from the combo box on the right).
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14       Raster Digitizer currently allows you to:
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16           ·   draw polygons, lines and points
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18           ·   set category value of the feature you are drawing
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20           ·   set  feature width (width of currently digitized line or diame‐
21               ter of a digitized point in map units)
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23           ·   create a new raster from scratch or from  an  already  existing
24               raster
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26           ·   undo edits and save edits before leaving the digitizer
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28       The typical workflow includes these steps:
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30       1      Set computational region as needed.
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32       2      Switch  to  Raster Digitizer and select a map to create.  Select
33              either a new raster or create a new raster from existing raster,
34              also select raster type (CELL, FCELL, DCELL)
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36       3      Specify category value and width before drawing a feature
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38       4      Specify digitizing tool (area, line, point)
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40       5      Start  digitizing  and when you want to finish area or line, use
41              right click
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43       6      Change color of temporary overlay depending on your needs
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45       7      Set different category and repeat
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47       8      At any point you can use Undo or Save
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49       9      If existing raster is used for the new raster,  digitized  areas
50              will  respect  the color table, but you can always set different
51              color table.
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NOTES

54       Raster Digitizer respects computational region including the  currently
55       set resolution.
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EXAMPLES

58       In  the  following  figures  we start with elev_lid792_1m raster map in
59       North carolina sample dataset and digitize two buildings, one rectangu‐
60       lar  and  one  with  circular  footprint.  Both buildings have the roof
61       level at 130 m. We set the width when digitizing the point to 50 meters
62       which  results  in  the  building having 50 m in diameter.  When we are
63       done with digitizing, we save the result and explore  cast  shadows  of
64       the buildings with r.sun module:
65       g.region raster=elev_lid792_1m
66       # now create elev_edited raster by digitizing and save
67       r.slope.aspect elevation=elev_edited slope=elev_slope aspect=elev_aspect
68       r.sun elevation=elev_edited aspect=elev_aspect slope=elev_slope beam_rad=beam day=172 time=6
69       Figure: Steps to digitize new buildings on elev_lid792_1m raster map.
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SEE ALSO

72        wxGUI
73       wxGUI components,
74       r.in.poly (backend of digitizer),
75       g.gui.vdigit
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AUTHOR

78       Anna Petrasova, NCSU GeoForALL Laboratory
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SOURCE CODE

81       Available at: wxGUI Raster Digitizer source code (history)
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83       Main  index  |  Wxgui index | Topics index | Keywords index | Graphical
84       index | Full index
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86       © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
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90GRASS 7.8.5                                                    wxGUI.rdigit(1)