Geografic-Information-System/temporal/t.rast.neighbors/t.rast.neighbors.html

<h2>DESCRIPTION</h2>

<em>t.rast.neighbors</em> performs <a href="r.neighbors.html">r.neighbors</a>
computations on the maps of a space time raster dataset (STRDS). This
module supports a subset of options that are available in
<a href="r.neighbors.html">r.neighbors</a>. The size of the neighborhood
and the aggregation method can be chosen.
<p>
The user must provide an input and an output space time raster dataset and
the basename of the resulting raster maps. The resulting STRDS will have
the same temporal resolution as the input dataset.
All maps will be processed using the current region settings.
<p>
The user can select a subset of the input space time raster dataset for
processing using a SQL WHERE statement. The number of CPU's to be used
for parallel processing can be specified with the <em>nprocs</em>
option to speedup the computation on multi-core system.


<h2>EXAMPLE</h2>

To smooth the maps contained in a space time dataset run:

<div class="code"><pre>
t.rast.neighbors input=tempmean_monthly output=smooth_tempmean_monthly \
                 basename=tmean_smooth size=5 method=average nprocs=4

# show some info about the new space time dataset
t.info smooth_tempmean_monthly
 +-------------------- Space Time Raster Dataset -----------------------------+
 |                                                                            |
 +-------------------- Basic information -------------------------------------+
 | Id: ........................ smooth_tempmean_monthly@climate_2000_2012
 | Name: ...................... smooth_tempmean_monthly
 | Mapset: .................... climate_2000_2012
 | Creator: ................... lucadelu
 | Temporal type: ............. absolute
 | Creation time: ............. 2014-11-27 11:41:36.444579
 | Modification time:.......... 2014-11-27 11:41:39.978232
 | Semantic type:.............. mean
 +-------------------- Absolute time -----------------------------------------+
 | Start time:................. 2009-01-01 00:00:00
 | End time:................... 2013-01-01 00:00:00
 | Granularity:................ 1 month
 | Temporal type of maps:...... interval
 +-------------------- Spatial extent ----------------------------------------+
 | North:...................... 320000.0
 | South:...................... 10000.0
 | East:.. .................... 935000.0
 | West:....................... 120000.0
 | Top:........................ 0.0
 | Bottom:..................... 0.0
 +-------------------- Metadata information ----------------------------------+
 | Raster register table:...... raster_map_register_ea1c9a83524e41a784d72744b08c6107
 | North-South resolution min:. 500.0
 | North-South resolution max:. 500.0
 | East-west resolution min:... 500.0
 | East-west resolution max:... 500.0
 | Minimum value min:.......... -6.428905
 | Minimum value max:.......... 18.867296
 | Maximum value min:.......... 4.247691
 | Maximum value max:.......... 28.767953
 | Aggregation type:........... None
 | Number of registered maps:.. 48
 |
 | Title:
 | Monthly precipitation
 | Description:
 | Dataset with monthly precipitation
 | Command history:
 | # 2014-11-27 11:41:36
 | t.rast.neighbors input="tempmean_monthly"
 |     output="smooth_tempmean_monthly" basename="tmean_smooth" size="5"
 |     method="average" nprocs="4"
 |
 +----------------------------------------------------------------------------+


# now compare the values between the original and the smoothed dataset

t.rast.list input=smooth_tempmean_monthly columns=name,start_time,min,max
name|start_time|min|max
tmean_smooth_1|2009-01-01 00:00:00|-3.361714|7.409861
tmean_smooth_2|2009-02-01 00:00:00|-1.820261|7.986794
tmean_smooth_3|2009-03-01 00:00:00|2.912971|11.799684
...
tmean_smooth_46|2012-10-01 00:00:00|9.38767|18.709297
tmean_smooth_47|2012-11-01 00:00:00|1.785653|10.911189
tmean_smooth_48|2012-12-01 00:00:00|1.784212|11.983857

t.rast.list input=tempmean_monthly columns=name,start_time,min,max
name|start_time|min|max
2009_01_tempmean|2009-01-01 00:00:00|-3.380823|7.426054
2009_02_tempmean|2009-02-01 00:00:00|-1.820261|8.006386
2009_03_tempmean|2009-03-01 00:00:00|2.656992|11.819274
...
2012_10_tempmean|2012-10-01 00:00:00|9.070884|18.709297
2012_11_tempmean|2012-11-01 00:00:00|1.785653|10.911189
2012_12_tempmean|2012-12-01 00:00:00|1.761019|11.983857
</pre></div>

<h2>SEE ALSO</h2>

<em>
<a href="r.neighbors.html">r.neighbors</a>,
<a href="t.rast.aggregate.ds.html">t.rast.aggregate.ds</a>,
<a href="t.rast.extract.html">t.rast.extract</a>,
<a href="t.info.html">t.info</a>,
<a href="g.region.html">g.region</a>,
<a href="r.mask.html">r.mask</a>
</em>


<h2>AUTHOR</h2>

S&ouml;ren Gebbert, Th&uuml;nen Institute of Climate-Smart Agriculture

<p><i>Last changed: $Date$</i>