|
@@ -36,19 +36,59 @@ calculating percentiles with large maps.
|
|
|
Computing univariate statistics of a 3D raster with randomly generated values:
|
|
|
|
|
|
<div class="code"><pre>
|
|
|
+# define volume
|
|
|
+g.region n=10 s=0 w=0 e=10 b=0 t=10 res=1 res3=1 -p3
|
|
|
+
|
|
|
# generate random map
|
|
|
r3.mapcalc "random_0_1 = rand(0., 1)" -s
|
|
|
|
|
|
-# compute univariate statistics
|
|
|
-r3.univar map=random_0_1
|
|
|
+# compute univariate statistics, along with extended statistics
|
|
|
+r3.univar -e map=random_0_1 percentile=98
|
|
|
+ 100%
|
|
|
+total null and non-null cells: 1000
|
|
|
+total null cells: 0
|
|
|
+
|
|
|
+Of the non-null cells:
|
|
|
+----------------------
|
|
|
+n: 1000
|
|
|
+minimum: 0.00053905
|
|
|
+maximum: 0.998322
|
|
|
+range: 0.997783
|
|
|
+mean: 0.513676
|
|
|
+mean of absolute values: 0.513676
|
|
|
+standard deviation: 0.289969
|
|
|
+variance: 0.0840821
|
|
|
+variation coefficient: 56.4498 %
|
|
|
+sum: 513.676463040334
|
|
|
+1st quartile: 0.257654
|
|
|
+median (even number of cells): 0.524313
|
|
|
+3rd quartile: 0.763637
|
|
|
+98th percentile: 0.982924
|
|
|
+
|
|
|
+# script style output, along with extended statistics
|
|
|
+r3.univar -ge map=random_0_1 percentile=98
|
|
|
+n=1000
|
|
|
+null_cells=0
|
|
|
+cells=1000
|
|
|
+min=0.000539049520323687
|
|
|
+max=0.998322037540536
|
|
|
+range=0.997782988020212
|
|
|
+mean=0.513676463040334
|
|
|
+mean_of_abs=0.513676463040334
|
|
|
+stddev=0.289969154194666
|
|
|
+variance=0.0840821103843701
|
|
|
+coeff_var=56.4497646005434
|
|
|
+sum=513.676463040334
|
|
|
+first_quartile=0.257654
|
|
|
+median=0.524313
|
|
|
+third_quartile=0.763637
|
|
|
+percentile_98=0.982924
|
|
|
</pre></div>
|
|
|
|
|
|
|
|
|
<h2>TODO</h2>
|
|
|
|
|
|
-<i>mode, skewness, kurtosis</i>
|
|
|
-
|
|
|
-
|
|
|
+To be implemented <i>mode, skewness, kurtosis</i>.
|
|
|
|
|
|
<h2>SEE ALSO</h2>
|
|
|
|
|
@@ -73,5 +113,4 @@ Hamish Bowman, Otago University, New Zealand<br>
|
|
|
and Martin Landa<br>
|
|
|
Zonal loop by Markus Metz
|
|
|
|
|
|
-
|
|
|
<p><i>Last changed: $Date$</i>
|