[GRASS-SVN] r62216 - grass/branches/releasebranch_7_0/raster/r.series
svn_grass at osgeo.org
svn_grass at osgeo.org
Wed Oct 8 12:19:37 PDT 2014
Author: neteler
Date: 2014-10-08 12:19:37 -0700 (Wed, 08 Oct 2014)
New Revision: 62216
Modified:
grass/branches/releasebranch_7_0/raster/r.series/r.series.html
Log:
r.series manual: cleanup; quantiles explained
Modified: grass/branches/releasebranch_7_0/raster/r.series/r.series.html
===================================================================
--- grass/branches/releasebranch_7_0/raster/r.series/r.series.html 2014-10-08 19:18:14 UTC (rev 62215)
+++ grass/branches/releasebranch_7_0/raster/r.series/r.series.html 2014-10-08 19:19:37 UTC (rev 62216)
@@ -2,6 +2,7 @@
<em>r.series</em> makes each output cell value a function of the values
assigned to the corresponding cells in the input raster map layers.
+<p>
Following methods are available:
<ul>
@@ -22,38 +23,80 @@
<li>tvalue: linear regression t-value
<li>min_raster: raster map number with the minimum time-series value
<li>max_raster: raster map number with the maximum time-series value
- </ul>
+</ul>
+Note that most parameters accept multiple answers, allowing multiple
+aggregates to be computed in a single run, e.g.:
+<p>
+<div class="code"><pre>
+r.series input=map1,...,mapN \
+ output=map.mean,map.stddev \
+ method=average,stddev
+</pre></div>
+
+or:
+<p>
+<div class="code"><pre>
+r.series input=map1,...,mapN \
+ output=map.p10,map.p50,map.p90 \
+ method=quantile,quantile,quantile \
+ quantile=0.1,0.5,0.9
+</pre></div>
+
+The same number of values must be provided for all options.
+
<h2>NOTES</h2>
-With <em>-n</em> flag, any cell for which any of the corresponding input cells are
-NULL is automatically set to NULL (NULL propagation). The aggregate function is not
-called, so all methods behave this way with respect to the <em>-n</em> flag.
-<p>Without <em>-n</em> flag, the complete list of inputs for each cell (including
-NULLs) is passed to the aggregate function. Individual aggregates can
-handle data as they choose. Mostly, they just compute the aggregate
-over the non-NULL values, producing a NULL result only if all inputs
-are NULL.
-<p>The <em>min_raster</em> and <em>max_raster</em> methods generate a map with the
-number of the raster map that holds the minimum/maximum value of the
-time-series. The numbering starts at <em>0</em> up to <em>n</em> for the
-first and the last raster listed in <em>input=</em>, respectively.
-<p>If the <em>range=</em> option is given, any values which fall outside
-that range will be treated as if they were NULL.
-The <em>range</em> parameter can be set to <em>low,high</em> thresholds:
-values outside of this range are treated as NULL (i.e., they will be
-ignored by most aggregates, or will cause the result to be NULL if -n is given).
-The <em>low,high</em> thresholds are floating point, so use <em>-inf</em> or
-<em>inf</em> for a single threshold (e.g., <em>range=0,inf</em> to ignore
-negative values, or <em>range=-inf,-200.4</em> to ignore values above -200.4).
-<p>Linear regression (slope, offset, coefficient of determination, t-value) assumes equal time intervals.
-If the data have irregular time intervals, NULL raster maps can be inserted into time series
-to make time intervals equal (see example).
+<h3>No-data (NULL) handling</h3>
+With <em>-n</em> flag, any cell for which any of the corresponding
+input cells are NULL is automatically set to NULL (NULL propagation).
+The aggregate function is not called, so all methods behave this way
+with respect to the <em>-n</em> flag.
+
<p>
+Without <em>-n</em> flag, the complete list of inputs for each cell
+(including NULLs) is passed to the aggregate function. Individual
+aggregates can handle data as they choose. Mostly, they just compute
+the aggregate over the non-NULL values, producing a NULL result only if
+all inputs are NULL.
+
+<h3>Minimum and maximum analysis</h3>
+The <em>min_raster</em> and <em>max_raster</em> methods generate a map
+with the number of the raster map that holds the minimum/maximum value
+of the time-series. The numbering starts at <em>0</em> up to <em>n</em>
+for the first and the last raster listed in <em>input=</em>,
+respectively.
+
+<h3>Range analysis</h3>
+If the <em>range=</em> option is given, any values which fall outside
+that range will be treated as if they were NULL. The <em>range</em>
+parameter can be set to <em>low,high</em> thresholds: values outside of
+this range are treated as NULL (i.e., they will be ignored by most
+aggregates, or will cause the result to be NULL if -n is given). The
+<em>low,high</em> thresholds are floating point, so use <em>-inf</em>
+or <em>inf</em> for a single threshold (e.g., <em>range=0,inf</em> to
+ignore negative values, or <em>range=-inf,-200.4</em> to ignore values
+above -200.4).
+
+<h3>Linear regression</h3>
+Linear regression (slope, offset, coefficient of determination,
+t-value) assumes equal time intervals. If the data have irregular time
+intervals, NULL raster maps can be inserted into time series to make
+time intervals equal (see example).
+
+<h3>Quantiles</h3>
+<em>r.series</em> can calculate arbitrary quantiles.
+
+<h3>Memory consumption</h3>
+
+Memory usage is not an issue, as <em>r.series</em> only needs to hold
+one row from each map at a time.
+
+<h3>Management of open file limits</h3>
Number of raster maps to be processed is given by the limit of the
operating system. For example, both the hard and soft limits are
-typically 1024. The soft limit can be changed with e.g. <tt>ulimit -n
-1500</tt> (UNIX-based operating systems) but not higher than the hard
+typically 1024. The soft limit can be changed with e.g. <tt>ulimit -n 1500</tt>
+(UNIX-based operating systems) but not higher than the hard
limit. If it is too low, you can as superuser add an entry in
<div class="code"><pre>
@@ -66,21 +109,23 @@
files open need more RAM. See also the Wiki page
<a href="http://grasswiki.osgeo.org/wiki/Large_raster_data_processing">Hints for large raster data processing</a>.
<p>
-For each map a weighting factor can be specified using the <em>weights</em> option.
-Using weights can be meaningful when computing sum or average of maps with different
-temporal extent. The default weight is 1.0. The number of weights must be identical
-with the number of input maps and must have the same order. Weights can also be specified in the
-input file.
+For each map a weighting factor can be specified using the
+<em>weights</em> option. Using weights can be meaningful when computing
+sum or average of maps with different temporal extent. The default
+weight is 1.0. The number of weights must be identical with the number
+of input maps and must have the same order. Weights can also be
+specified in the input file.
<p>
-Use the <em>file</em> option to analyze large amount of raster maps
-without hitting open files limit and the size limit of command line arguments.
-The computation is slower than the <em>input</em> option method.
-For every sinlge row in the output map(s)
-all input maps are opened and closed. The amount of RAM will rise linear
-with the number of specified input maps. The input and file options are mutually exclusive.
-Input is a text file with a new line separated list of raster map names and optional weights.
-As separator between the map name and the weight the character "|" must be used.
+Use the <em>file</em> option to analyze large amount of raster maps
+without hitting open files limit and the size limit of command line
+arguments. The computation is slower than the <em>input</em> option
+method. For every sinlge row in the output map(s) all input maps are
+opened and closed. The amount of RAM will rise linear with the number
+of specified input maps. The input and file options are mutually
+exclusive. Input is a text file with a new line separated list of
+raster map names and optional weights. As separator between the map
+name and the weight the character "|" must be used.
<h2>EXAMPLES</h2>
@@ -90,9 +135,13 @@
r.series input="`g.mlist pattern='insitu_data.*' sep=,`" \
output=insitu_data.stddev method=stddev
</pre></div>
-<p>Note the <em>g.mlist</em> script also supports regular expressions for
+<p>
+Note the <em>g.mlist</em> script also supports regular expressions for
selecting map names.
-<p>Using <em>r.series</em> with NULL raster maps:
+
+<p>
+Using <em>r.series</em> with NULL raster maps (in order to consider a
+"complete" time series):
<br>
<div class="code"><pre>
r.mapcalc "dummy = null()"
@@ -117,8 +166,11 @@
r.series file=input.txt out=result_sum meth=sum
</pre></div>
-<p>Example to use the file option of r.series including weights. The weight 0.75
-should be assigned to map2. As the other maps do not have weights we can leave it out:
+<p>
+Example to use the file option of r.series including weights. The
+weight 0.75 should be assigned to map2. As the other maps do not have
+weights we can leave it out:
+
<div class="code"><pre>
cat > input.txt << EOF
map1
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