[GRASS-SVN] r53047 - grass/trunk/raster/r.grow.distance
svn_grass at osgeo.org
svn_grass at osgeo.org
Sat Sep 1 03:51:32 PDT 2012
Author: neteler
Date: 2012-09-01 03:51:31 -0700 (Sat, 01 Sep 2012)
New Revision: 53047
Modified:
grass/trunk/raster/r.grow.distance/r.grow.distance.html
Log:
manual prettified
Modified: grass/trunk/raster/r.grow.distance/r.grow.distance.html
===================================================================
--- grass/trunk/raster/r.grow.distance/r.grow.distance.html 2012-09-01 10:48:14 UTC (rev 53046)
+++ grass/trunk/raster/r.grow.distance/r.grow.distance.html 2012-09-01 10:51:31 UTC (rev 53047)
@@ -16,12 +16,15 @@
proven by repeated application of the Pythagorean theorem.
The formula is given by:
-<div class="code"><pre>d(dx,dy) = sqrt(dx^2 + dy^2)</pre></div>
+<div class="code"><pre>
+d(dx,dy) = sqrt(dx^2 + dy^2)
+</pre></div>
Cells grown using this metric would form isolines of distance that are
circular from a given point, with the distance given by the <b>radius</b>.
-<p>The <i>Squared</i> metric is the <i>Euclidean</i> distance squared,
+<p>
+The <i>Squared</i> metric is the <i>Euclidean</i> distance squared,
i.e. it simply omits the square-root calculation. This may be faster,
and is sufficient if only relative values are required.
@@ -35,7 +38,9 @@
points' distance in taxicab geometry.
The formula is given by:
-<div class="code"><pre>d(dx,dy) = abs(dx) + abs(dy)</pre></div>
+<div class="code"><pre>
+d(dx,dy) = abs(dx) + abs(dy)
+</pre></div>
where cells grown using this metric would form isolines of distance that are
rhombus-shaped from a given point.
@@ -43,25 +48,28 @@
<p>
The <i>Maximum metric</i> is given by the formula
-<div class="code"><pre>d(dx,dy) = max(abs(dx),abs(dy))</pre></div>
+<div class="code"><pre>
+d(dx,dy) = max(abs(dx),abs(dy))
+</pre></div>
where the isolines of distance from a point are squares.
<h2>EXAMPLE</h2>
-Spearfish sample dataset
+Distance from the streams network (North Carolina sample dataset):
<div class="code"><pre>
-r.grow.distance in=roads dist=dist_from_roads
+g.region rast=streams_derived -p
+r.grow.distance input=streams_derived distance=dist_from_streams
</pre></div>
<h2>SEE ALSO</h2>
<em>
-<a href="r.grow.html">r.grow</a><br>
-<a href="r.buffer.html">r.buffer</a><br>
-<a href="r.cost.html">r.cost</a><br>
+<a href="r.grow.html">r.grow</a>,
+<a href="r.buffer.html">r.buffer</a>,
+<a href="r.cost.html">r.cost</a>,
<a href="r.patch.html">r.patch</a>
</em>
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