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- <h2>DESCRIPTION</h2>
- The <em>d.rast.edit</em> program allows users to interactively
- edit cell category values in a raster map layer displayed to the
- graphics monitor using a mouse cursor.
- <h3>Overview window</h3>
- An overview window shows the entire map with a red box showing the current
- editing region. The edit window shows the cells within the selected area.
- Click on a new spot on the overview window to move the editing area.
- <h3>Raster cell editing</h3>
- Cell editing is done using the mouse cursor to indicate the cell(s) on
- the displayed raster map that are to be edited.
- <p>
- To change the value of a cell put the new value to use in the "New value"
- box at the bottom left of the edit window. A value of "*" indicates a
- NULL value should be used.
- <p>
- <b>Important:</b> the new value in the "New value" box must be confirmed
- with ENTER, otherwise it is not yet active.
- <h3>Saving the edited map</h3>
- To save the edited map, the "File" menu contains the entry <b>Save</b>.
- To leave <em>d.rast.edit</em>, use <b>Exit</b> in the menu.
- <h3>Map pan with arrow keys</h3>
- The map can be shifted using the arrow keys on the keyboard.
- <!-- currently broken, see #
- <h3>Arrows</h3>
- This function is available for users editing aspect maps. The
- <em><a href="d.rast.arrow.html">d.rast.arrow</a></em> program is
- called, which draws arrows over the displayed
- cells to indicate the downslope direction of the cell.
- You can set the aspect map to use on the command line.
- Aspect maps are expected to be in regular "GRASS" format, as produced by
- <em><a href="r.slope.aspect.html">r.slope.aspect</a></em>; i.e. degrees
- counter-clockwise from east.
- -->
- <h2>NOTES</h2>
- There is no "undo" command nor way to exit edit mode without saving
- changes to the output map.
- <p>
- <!-- MASK behaviour to be verified -->
- Any MASK in place will be respected when writing the new raster map layer,
- including any edits to the MASKed areas.
- <h3>Geographic Region Concerns</h3>
- <!-- region behaviour to be verified -->
- <em>d.rast.edit</em> reads the region definition for the raster map layer
- being edited from its internal cell header file. The new, edited copy of
- the raster layer will be created with the same resolution and region
- dimensions.
- <p>The primary bane of the <em>d.rast.edit</em> program involves large map
- layers with lots of rows and columns) and/or slow computers,
- since the program must read and write raster map layers row by row for
- the full size of the map layer as dictated by its region size and resolution.
- (The current region settings of north, south, east, and west
- will not limit the size of the edited copy of the map layer,
- since by use of the overview selection these values may change several
- times during the editing session).
- <h2>EXAMPLE</h2>
- Editing raster values in a LiDAR DEM, North Carolina sample data:
- <div class="code"><pre>
- g.region raster=elev_lid792_1m -p
- # pan to area of interest and edit raster cells (I used "102" as value to modifiy cells
- # Use: File > Save to save
- # then: File > Exit
- d.rast.edit input=elev_lid792_1m output=elev_lid792_1m_modified
- # comparison of raster statistics
- # original stats, note the min value
- r.univar -g elev_lid792_1m
- # modified map stats, note the min value
- r.univar -g elev_lid792_1m_modified
- </pre></div>
- <div align="center" style="margin: 10px">
- <a href="d_rast_edit.png">
- <img src="d_rast_edit.png" width="600" height="281" alt="d.rast.edit example" border="0">
- </a><br>
- <i>Figure: Editing of pixels in an elevation raster map using d.rast.edit</i>
- </div>
- <h2>TODO</h2>
- <em>d.rast.edit</em> should not create a new raster map layer if
- the user makes no cell edits while running the program and leaving it
- without saving.
- <p>
- It would be nice to incorporate a scrollable version of <em>
- <a href="d.legend.html">d.legend</a>
- </em>
- (such that one could see a label legend for files with many categories on
- a standard size sub-frame). It would be even nicer to be able
- to select the category values from a graphical legend when editing
- cell values (thereby saving a trip to the text frame to type in the
- new value).
- <p>Perhaps method(s) for multiple or mass cell edits would be useful.
- This could be done by providing modes in which the user may:
- <ol>
- <li> edit a block of cells to a given value by drawing a box;</li>
- <li> be able to choose a given value which is automatically used as
- the new value on each cell chosen until a different value is desired.</li>
- </ol>
- <p>There is no user-interrupt handling. This could leave files in .tmp
- or (rarely) result in half-baked raster maps. The original file
- would survive unscathed by an interrupt at most any point in execution.
- Beware of exiting the program
- by means other than using <em>exit</em> on the <em>Main Menu</em>.
- <h2>SEE ALSO</h2>
- <em>
- <a href="d.rast.arrow.html">d.rast.arrow</a>,
- <a href="d.rast.num.html">d.rast.num</a>,
- <a href="wxGUI.rdigit.html">wxGUI.rdigit</a>
- </em>
- <h2>AUTHOR</h2>
- Tcl/Tk (2007) and wxPython versions (2008): Glynn Clements<br>
- <br>
- Replaces Xdriver version in C by Chris Rewerts, April 1991,
- Agricultural Engineering, Purdue University
- <!--
- <p>
- <i>Last changed: $Date$</i>
- -->
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