1t.rast.neighbors(1) GRASS GIS User's Manual t.rast.neighbors(1)
2
6 t.rast.neighbors - Performs a neighborhood analysis for each map in a
7 space time raster dataset.
8
10 temporal, aggregation, raster, time
11
13 t.rast.neighbors
14 t.rast.neighbors --help
15 t.rast.neighbors [-nr] input=name output=name [where=sql_query]
16 [size=integer] method=string basename=string [suffix=string] [se‐
17 mantic_labels=string] [nprocs=integer] [--overwrite] [--help]
18 [--verbose] [--quiet] [--ui]
19 Flags:
21 -n
22 Register Null maps
23 -r
25 Ignore the current region settings and use the raster map regions
26 --overwrite
28 Allow output files to overwrite existing files
29 --help
31 Print usage summary
32 --verbose
34 Verbose module output
35 --quiet
37 Quiet module output
38 --ui
40 Force launching GUI dialog
41 Parameters:
43 input=name [required]
44 Name of the input space time raster dataset
45 output=name [required]
47 Name of the output space time raster dataset
48 where=sql_query
50 WHERE conditions of SQL statement without ’where’ keyword used in
51 the temporal GIS framework
52 Example: start_time > ’2001-01-01 12:30:00’
53 size=integer
55 Neighborhood size
56 Default: 3
57 method=string [required]
59 Aggregate operation to be performed on the raster maps
60 Options: average, median, mode, minimum, maximum, range, stddev,
61 sum, count, variance, diversity, interspersion, quart1, quart3,
62 perc90, quantile
63 Default: average
64 basename=string [required]
66 Basename of the new generated output maps
67 A numerical suffix separated by an underscore will be attached to
68 create a unique identifier
69 suffix=string
71 Suffix to add at basename: set ’gran’ for granularity, ’time’ for
72 the full time format, ’num’ for numerical suffix with a specific
73 number of digits (default %05)
74 Default: gran
75 semantic_labels=string
77 Set semantic labels
78 Options: input, method
79 Default: input
80 input: copy semantic labels from input to output
81 method: append method name to input label if existing, otherwise
82 use method name
83 nprocs=integer
85 Number of r.neighbor processes to run in parallel
86 Default: 1
87
89 t.rast.neighbors performs r.neighbors computations on the maps of a
90 space time raster dataset (STRDS). This module supports a subset of op‐
91 tions that are available in r.neighbors. The size of the neighborhood
92 and the aggregation method can be chosen.
93 The user must provide an input and an output space time raster dataset
95 and the basename of the resulting raster maps. The resulting STRDS will
96 have the same temporal resolution as the input dataset. All maps will
97 be processed using the current region settings.
98 The user can select a subset of the input space time raster dataset for
100 processing using a SQL WHERE statement. The number of CPU’s to be used
101 for parallel processing can be specified with the nprocs option to
102 speedup the computation on multi-core system.
103 Semantic labels are needed to relate output raster maps to input raster
105 maps. E.g. with method=stddev, the user needs to know the spatial ex‐
106 tent, the time stamp and the semantic label to determine which stddev
107 map corresponds to which input map.
108
110 To smooth the maps contained in a space time dataset run:
111 t.rast.neighbors input=tempmean_monthly output=smooth_tempmean_monthly \
112 basename=tmean_smooth size=5 method=average nprocs=4
113 # show some info about the new space time dataset
114 t.info smooth_tempmean_monthly
115 +-------------------- Space Time Raster Dataset -----------------------------+
116 | |
117 +-------------------- Basic information -------------------------------------+
118 | Id: ........................ smooth_tempmean_monthly@climate_2000_2012
119 | Name: ...................... smooth_tempmean_monthly
120 | Mapset: .................... climate_2000_2012
121 | Creator: ................... lucadelu
122 | Temporal type: ............. absolute
123 | Creation time: ............. 2014-11-27 11:41:36.444579
124 | Modification time:.......... 2014-11-27 11:41:39.978232
125 | Semantic type:.............. mean
126 +-------------------- Absolute time -----------------------------------------+
127 | Start time:................. 2009-01-01 00:00:00
128 | End time:................... 2013-01-01 00:00:00
129 | Granularity:................ 1 month
130 | Temporal type of maps:...... interval
131 +-------------------- Spatial extent ----------------------------------------+
132 | North:...................... 320000.0
133 | South:...................... 10000.0
134 | East:.. .................... 935000.0
135 | West:....................... 120000.0
136 | Top:........................ 0.0
137 | Bottom:..................... 0.0
138 +-------------------- Metadata information ----------------------------------+
139 | Raster register table:...... raster_map_register_ea1c9a83524e41a784d72744b08c6107
140 | North-South resolution min:. 500.0
141 | North-South resolution max:. 500.0
142 | East-west resolution min:... 500.0
143 | East-west resolution max:... 500.0
144 | Minimum value min:.......... -6.428905
145 | Minimum value max:.......... 18.867296
146 | Maximum value min:.......... 4.247691
147 | Maximum value max:.......... 28.767953
148 | Aggregation type:........... None
149 | Number of registered maps:.. 48
150 |
151 | Title:
152 | Monthly precipitation
153 | Description:
154 | Dataset with monthly precipitation
155 | Command history:
156 | # 2014-11-27 11:41:36
157 | t.rast.neighbors input="tempmean_monthly"
158 | output="smooth_tempmean_monthly" basename="tmean_smooth" size="5"
159 | method="average" nprocs="4"
160 |
161 +----------------------------------------------------------------------------+
162 # now compare the values between the original and the smoothed dataset
163 t.rast.list input=smooth_tempmean_monthly columns=name,start_time,min,max
164 name|start_time|min|max
165 tmean_smooth_1|2009-01-01 00:00:00|-3.361714|7.409861
166 tmean_smooth_2|2009-02-01 00:00:00|-1.820261|7.986794
167 tmean_smooth_3|2009-03-01 00:00:00|2.912971|11.799684
168 ...
169 tmean_smooth_46|2012-10-01 00:00:00|9.38767|18.709297
170 tmean_smooth_47|2012-11-01 00:00:00|1.785653|10.911189
171 tmean_smooth_48|2012-12-01 00:00:00|1.784212|11.983857
172 t.rast.list input=tempmean_monthly columns=name,start_time,min,max
173 name|start_time|min|max
174 2009_01_tempmean|2009-01-01 00:00:00|-3.380823|7.426054
175 2009_02_tempmean|2009-02-01 00:00:00|-1.820261|8.006386
176 2009_03_tempmean|2009-03-01 00:00:00|2.656992|11.819274
177 ...
178 2012_10_tempmean|2012-10-01 00:00:00|9.070884|18.709297
179 2012_11_tempmean|2012-11-01 00:00:00|1.785653|10.911189
180 2012_12_tempmean|2012-12-01 00:00:00|1.761019|11.983857
181
183 r.neighbors, t.rast.aggregate.ds, t.rast.extract, t.info, g.region,
184 r.mask
185
187 Sören Gebbert, Thünen Institute of Climate-Smart Agriculture
188
190 Available at: t.rast.neighbors source code (history)
191 Accessed: Mon Jun 20 16:47:47 2022
193 Main index | Temporal index | Topics index | Keywords index | Graphical
195 index | Full index
196 © 2003-2022 GRASS Development Team, GRASS GIS 8.2.0 Reference Manual
198GRASS 8.2.0 t.rast.neighbors(1)