|
@@ -17,7 +17,9 @@ match three criteria and to define the lake:
|
|
|
|
|
|
<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 @@ Specifying a target water level below surface represented by DEM will result in
|
|
|
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.
|
|
|
-It equals the mapcalc's expression <em>"negative = 0 - positive"</em>.</p>
|
|
|
+<p>
|
|
|
|
|
|
-<h2>KNOWN BUGS AND LIMITATIONS</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>
|
|
|
+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>MAPCALC EQUIVALENT - FOR GRASS HACKERS</h2>
|
|
|
+<h3>MAPCALC EQUIVALENT - FOR GRASS HACKERS</h3>
|
|
|
|
|
|
-<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 @@ ${wlevel} with target water level. To get single water level, this code block i
|
|
|
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>,
|