[GRASS-SVN] r31494 - grass/trunk/raster/r.lake
svn_grass at osgeo.org
svn_grass at osgeo.org
Fri May 23 10:34:57 EDT 2008
Author: epatton
Date: 2008-05-23 10:34:56 -0400 (Fri, 23 May 2008)
New Revision: 31494
Modified:
grass/trunk/raster/r.lake/description.html
Log:
Reorganized sections headings, HTML tag cleaning
Modified: grass/trunk/raster/r.lake/description.html
===================================================================
--- grass/trunk/raster/r.lake/description.html 2008-05-23 13:01:51 UTC (rev 31493)
+++ grass/trunk/raster/r.lake/description.html 2008-05-23 14:34:56 UTC (rev 31494)
@@ -17,7 +17,9 @@
<p>The water level must be in DEM units.</p>
-<p>The seed (starting) point can be a raster map with at least one
+<h2>NOTES</h2>
+
+The seed (starting) point can be a raster map with at least one
cell value greater than zero, or a seed point can be specified as an E,
N coordinate pair. If the seed is specified as a coordinate pair, an additional
check is done to make sure that the target water level is above the level of
@@ -26,28 +28,23 @@
empty map. Note: a raster lake map created in a previous run can also be used
as a seed map for a new run to simulate rising water levels.</p>
-<p>The module will create a new map (<em>lake=foo</em>) or can be set to replace
-the input (<em>seed=bar</em>) map if the <em>-o</em> flag is used. The user can use
-<em>-o</em> flag to create animations of rising water level without
+<p>
+
+The module will create a new map (<b>lake=foo</b>) or can be set to replace
+the input (<b>seed=bar</b>) map if the <b>-o</b> flag is used. The user can use
+<b>-o</b> flag to create animations of rising water level without
producing a separate map for each frame. An initial seed map must be created
to start the sequence, and will be overwritten during subsequent runs with resulting
water levels maps (i.e., a single file serves for both input and output).</p>
-<p>Negative output (the <em>-n</em> flag) is useful for visualisations in NVIZ.
+<p>
+
+Negative output (the <b>-n</b> flag) is useful for visualisations in NVIZ.
It equals the mapcalc's expression <em>"negative = 0 - positive"</em>.</p>
-<h2>KNOWN BUGS AND LIMITATIONS</h2>
+<h3>MAPCALC EQUIVALENT - FOR GRASS HACKERS</h3>
-<ul>
- <li>The entire map is loaded into RAM.</li>
- <li>The module is NOT large file safe. (due to the previous point)</li>
- <li>A completely negative seed map will not work! At least one cell must have
- a value >0. Output from <em>r.lake -n</em> can NOT be used as input in the next run.</li>
-</ul>
-
-<h2>MAPCALC EQUIVALENT - FOR GRASS HACKERS</h2>
-
-<p>This module was initially created as a script using
+This module was initially created as a script using
<em>r.mapcalc</em>. This had some limitations - it was slow and no
checks where done to find out required iteration count. The shell script
code (using <em>r.mapcalc</em>) used in the original script is shown below:
@@ -72,6 +69,15 @@
called with same level numerous times (in a loop) as the lake grows by single cells
during single run.</p>
+<h2>BUGS/KNOWN ISSUES</h2>
+
+<ul>
+ <li>The entire map is loaded into RAM.</li>
+ <li>The module is NOT large file safe. (due to the previous point)</li>
+ <li>A completely negative seed map will not work! At least one cell must have
+ a value >0. Output from <em>r.lake -n</em> can NOT be used as input in the next run.</li>
+</ul>
+
<h2>SEE ALSO</h2>
<em><a href="r.mapcalc.html">r.mapcalc</a>,
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