r.univar and r3.univar: mention sum in manual, use 3D raster term, add trivial example for r3.univar

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@62185 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.univar/r.univar.html

@@ -2,8 +2,8 @@
 
 <em>r.univar</em> calculates the univariate statistics of one or several raster
 map(s). This includes the number of cells counted, minimum and maximum cell
-values, range, arithmetic mean, population variance, standard deviation, and 
-coefficient of variation. Statistics are calculated separately for every
+values, range, arithmetic mean, population variance, standard deviation,
+coefficient of variation, and sum. Statistics are calculated separately for every
 category/zone found in the <b>zones</b> input map if given.
 If the <b>-e</b> extended statistics flag is given the 1st quartile, median,
 3rd quartile, and given <b>percentile</b> are calculated.

raster/r.univar/r3.univar.html

@@ -1,9 +1,9 @@
 <h2>DESCRIPTION</h2>
 
-<em>r3.univar</em> calculates the univariate statistics for raster3d maps.
+<em>r3.univar</em> calculates the univariate statistics for a 3D raster map.
 This includes the number of cells counted, minimum and maximum cell values,
-range, arithmetic mean, population variance, standard deviation, and 
-coefficient of variation. Statistics are calculated separately for every
+range, arithmetic mean, population variance, standard deviation,
+coefficient of variation, and sum. Statistics are calculated separately for every
 category/zone found in the <b>zones</b> input map if given.
 If the <b>-e</b> extended statistics flag is given the 1st quartile, median,
 3rd quartile, and given <b>percentile</b> are calculated.
@@ -31,6 +31,19 @@ The <em>r.quantile</em> module will be significantly more efficient for
 calculating percentiles with large maps.
 -->
 
+<h2>EXAMPLE</h2>
+
+Computing univariate statistics of a 3D raster with randomly generated values:
+
+<div class="code"><pre>
+# generate random map
+r3.mapcalc "random_0_1 = rand(0., 1)" -s
+
+# compute univariate statistics
+r3.univar map=random_0_1
+</pre></div>
+
+
 <h2>TODO</h2>
 
 <i>mode, skewness, kurtosis</i>

raster/r.univar/r3.univar_main.c

@@ -100,7 +100,7 @@ int main(int argc, char *argv[])
     G_add_keyword(_("univariate statistics"));
 
     module->description =
-	_("Calculates univariate statistics from the non-null 3d cells of a raster3d map.");
+	_("Calculates univariate statistics from the non-null cells of a 3D raster map.");
 
     /* Define the different options */
     set_params();