[GRASS-SVN] r65574 - grass/branches/releasebranch_7_0/raster/r.slope.aspect
svn_grass at osgeo.org
svn_grass at osgeo.org
Sat Jul 11 06:00:17 PDT 2015
Author: neteler
Date: 2015-07-11 06:00:17 -0700 (Sat, 11 Jul 2015)
New Revision: 65574
Modified:
grass/branches/releasebranch_7_0/raster/r.slope.aspect/r.slope.aspect.html
Log:
r.slope.aspect manual: cosmetics for hint on transformation of ccw aspect to azimuth (r65553 + r65573)
Modified: grass/branches/releasebranch_7_0/raster/r.slope.aspect/r.slope.aspect.html
===================================================================
--- grass/branches/releasebranch_7_0/raster/r.slope.aspect/r.slope.aspect.html 2015-07-11 12:59:25 UTC (rev 65573)
+++ grass/branches/releasebranch_7_0/raster/r.slope.aspect/r.slope.aspect.html 2015-07-11 13:00:17 UTC (rev 65574)
@@ -22,8 +22,15 @@
facing. The aspect categories represent the number degrees of east. Category
and color table files are also generated for the aspect raster map. The aspect
categories represent the number degrees of east and they increase
-counterclockwise: 90 degrees is North, 180 is West, 270 is South 360 is East.
+counterclockwise: 90 degrees is North, 180 is West, 270 is South 360 is East.<br>
+Note: These values can be transformed to azimuth (0 is North, 90 is East, etc)
+values using <a href="r.mapcalc.html">r.mapcalc</a>:
+<div class="code"><pre>
+# convert angles from CCW to north up
+r.mapcalc "azimuth_aspect = (450 - ccw_aspect) % 360"
+</pre></div>
+
<p>
The aspect is not defined for slope equal to zero.
Thus, most cells with a very small slope end up having category 0,
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