1t.sample(1) GRASS GIS User's Manual t.sample(1)
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6 t.sample - Samples the input space time dataset(s) with a sample space
7 time dataset and print the result to stdout.
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10 temporal, sampling, time
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13 t.sample
14 t.sample --help
15 t.sample [-cs] inputs=name[,name,...] sample=name [intype=name]
16 [samtype=name] [method=name[,name,...]] [separator=character]
17 [--help] [--verbose] [--quiet] [--ui]
18
19 Flags:
20 -c
21 Print the column names as first row
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23 -s
24 Check for spatial topological overlap
25
26 --help
27 Print usage summary
28
29 --verbose
30 Verbose module output
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32 --quiet
33 Quiet module output
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35 --ui
36 Force launching GUI dialog
37
38 Parameters:
39 inputs=name[,name,...]Â [required]
40 Name of the input space time datasets
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42 sample=name [required]
43 Name of the sample space time dataset
44
45 intype=name
46 Type of the input space time dataset
47 Options: strds, stvds, str3ds
48 Default: strds
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50 samtype=name
51 Type of the sample space time dataset
52 Options: strds, stvds, str3ds
53 Default: strds
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55 method=name[,name,...]
56 The method to be used for sampling the input dataset
57 Options: start, during, overlap, contain, equal, follows, precedes
58 Default: during,overlap,contain,equal
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60 separator=character
61 Do not use "," as this char is reserved to list several map ids in
62 a sample granule
63 Field separator between output columns, default is tabular " | "
64 Default: pipe
65
67 The purpose of this module is to compute and to show spatio-temporal
68 relations between space time datasets of different type. Several input
69 space time datasets are sampled by a sample space time dataset using
70 temporal topological relations. The types of the input space time
71 datasets and the type of the sample space time dataset can be differ‐
72 ent.
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74 This module is useful to analyze temporal relationships between space
75 time datasets using temporal topology. The flag -s enables a spa‐
76 tio-temporal topology, so that only spatio-temporal related map layers
77 of space time datasets are considered in the analysis.
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80 The temporal relation start means that the start time of an input map
81 layer is temporally located in an interval of a sample map layer.
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83 The textual output at the command line shows the names of the maps,
84 start and end time as well as the interval length in days and the tem‐
85 poral distance from begin in days.
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87 The default separator is the pipe symbol.
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89 Temporal gaps, if present, in the input and sampling space time
90 datasets will be used in the sampling process. Gaps have no map name,
91 instead None is printed.
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94 In the examples below we create a space time raster dataset A and a
95 space time vector dataset P that have different temporal layouts and
96 number of map layers. The space time vector dataset contains a gap,
97 that will be used in the sampling process.
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99 We use t.sample to inspect the topological relations between the time
100 stamped map layers in A and P.
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102 # Set an appropriate region
103 g.region s=0 n=80 w=0 e=120 b=0 t=50 res=10 res3=10 -p3
104 # Generate the raster map layer
105 r.mapcalc expression="a1 = rand(0, 550)" -s
106 r.mapcalc expression="a2 = rand(0, 450)" -s
107 r.mapcalc expression="a3 = rand(0, 320)" -s
108 r.mapcalc expression="a4 = rand(0, 510)" -s
109 r.mapcalc expression="a5 = rand(0, 300)" -s
110 r.mapcalc expression="a6 = rand(0, 650)" -s
111 # Generate the vector map layer
112 v.random -z output=pnts1 n=20 zmin=0 zmax=100 column=height
113 v.random -z output=pnts2 n=20 zmin=0 zmax=100 column=height
114 n1=`g.tempfile pid=1 -d`
115 n2=`g.tempfile pid=2 -d`
116 cat > "${n1}" << EOF
117 a1
118 a2
119 a3
120 a4
121 a5
122 a6
123 EOF
124 cat > "${n2}" << EOF
125 pnts1|2001-01-01|2001-03-01
126 pnts2|2001-05-01|2001-07-01
127 EOF
128 # Register the maps in new space time datasets
129 t.create type=strds temporaltype=absolute output=A \
130 title="A test with raster input files" descr="A test with raster input files"
131 t.create type=stvds temporaltype=absolute output=P \
132 title="A test with vector input files" descr="A test with vector input files"
133 t.register type=raster -i input=A file="${n1}" start="2001-01-01" increment="1 months"
134 # Raster map layer in A
135 t.rast.list A
136 name|mapset|start_time|end_time
137 a1|PERMANENT|2001-01-01 00:00:00|2001-02-01 00:00:00
138 a2|PERMANENT|2001-02-01 00:00:00|2001-03-01 00:00:00
139 a3|PERMANENT|2001-03-01 00:00:00|2001-04-01 00:00:00
140 a4|PERMANENT|2001-04-01 00:00:00|2001-05-01 00:00:00
141 a5|PERMANENT|2001-05-01 00:00:00|2001-06-01 00:00:00
142 a6|PERMANENT|2001-06-01 00:00:00|2001-07-01 00:00:00
143 t.register type=vector input=P file="${n2}"
144 # Vector map layer in P
145 t.vect.list P
146 name|layer|mapset|start_time|end_time
147 pnts1|None|PERMANENT|2001-01-01 00:00:00|2001-03-01 00:00:00
148 pnts2|None|PERMANENT|2001-05-01 00:00:00|2001-07-01 00:00:00
149 # Start time of maps in A located in maps in P
150 t.sample method=start input=A samtype=stvds sample=P -c
151 P@PERMANENT|A@PERMANENT|start_time|end_time|interval_length|distance_from_begin
152 pnts1@PERMANENT|a1@PERMANENT,a2@PERMANENT|2001-01-01 00:00:00|2001-03-01 00:00:00|59.0|0.0
153 None|a3@PERMANENT,a4@PERMANENT|2001-03-01 00:00:00|2001-05-01 00:00:00|61.0|59.0
154 pnts2@PERMANENT|a5@PERMANENT,a6@PERMANENT|2001-05-01 00:00:00|2001-07-01 00:00:00|61.0|120.0
155 # P contains A
156 t.sample method=contain input=A samtype=stvds sample=P -c
157 P@PERMANENT|A@PERMANENT|start_time|end_time|interval_length|distance_from_begin
158 pnts1@PERMANENT|a1@PERMANENT,a2@PERMANENT|2001-01-01 00:00:00|2001-03-01 00:00:00|59.0|0.0
159 None|a3@PERMANENT,a4@PERMANENT|2001-03-01 00:00:00|2001-05-01 00:00:00|61.0|59.0
160 pnts2@PERMANENT|a5@PERMANENT,a6@PERMANENT|2001-05-01 00:00:00|2001-07-01 00:00:00|61.0|120.0
161 # A during P
162 t.sample method=during intype=stvds input=P samtype=strds sample=A -c
163 A@PERMANENT|P@PERMANENT|start_time|end_time|interval_length|distance_from_begin
164 a1@PERMANENT|pnts1@PERMANENT|2001-01-01 00:00:00|2001-02-01 00:00:00|31.0|0.0
165 a2@PERMANENT|pnts1@PERMANENT|2001-02-01 00:00:00|2001-03-01 00:00:00|28.0|31.0
166 a3@PERMANENT|None|2001-03-01 00:00:00|2001-04-01 00:00:00|31.0|59.0
167 a4@PERMANENT|None|2001-04-01 00:00:00|2001-05-01 00:00:00|30.0|90.0
168 a5@PERMANENT|pnts2@PERMANENT|2001-05-01 00:00:00|2001-06-01 00:00:00|31.0|120.0
169 a6@PERMANENT|pnts2@PERMANENT|2001-06-01 00:00:00|2001-07-01 00:00:00|30.0|151.0
170 # No Overlapping
171 t.sample method=overlap input=A samtype=stvds sample=P -cs
172 P@PERMANENT|A@PERMANENT|start_time|end_time|interval_length|distance_from_begin
173 pnts1@PERMANENT|None|2001-01-01 00:00:00|2001-03-01 00:00:00|59.0|0.0
174 None|None|2001-03-01 00:00:00|2001-05-01 00:00:00|61.0|59.0
175 pnts2@PERMANENT|None|2001-05-01 00:00:00|2001-07-01 00:00:00|61.0|120.0
176 t.sample method=precedes input=A samtype=stvds sample=P -c
177 P@PERMANENT|A@PERMANENT|start_time|end_time|interval_length|distance_from_begin
178 pnts1@PERMANENT|a3@PERMANENT|2001-01-01 00:00:00|2001-03-01 00:00:00|59.0|0.0
179 None|a5@PERMANENT|2001-03-01 00:00:00|2001-05-01 00:00:00|61.0|59.0
180 pnts2@PERMANENT|None|2001-05-01 00:00:00|2001-07-01 00:00:00|61.0|120.0
181 t.sample method=follows input=A samtype=stvds sample=P -c
182 P@PERMANENT|A@PERMANENT|start_time|end_time|interval_length|distance_from_begin
183 pnts1@PERMANENT|None|2001-01-01 00:00:00|2001-03-01 00:00:00|59.0|0.0
184 None|a2@PERMANENT|2001-03-01 00:00:00|2001-05-01 00:00:00|61.0|59.0
185 pnts2@PERMANENT|a4@PERMANENT|2001-05-01 00:00:00|2001-07-01 00:00:00|61.0|120.0
186 t.sample method=precedes,follows input=A samtype=stvds sample=P -c
187 P@PERMANENT|A@PERMANENT|start_time|end_time|interval_length|distance_from_begin
188 pnts1@PERMANENT|a3@PERMANENT|2001-01-01 00:00:00|2001-03-01 00:00:00|59.0|0.0
189 None|a5@PERMANENT,a2@PERMANENT|2001-03-01 00:00:00|2001-05-01 00:00:00|61.0|59.0
190 pnts2@PERMANENT|a4@PERMANENT|2001-05-01 00:00:00|2001-07-01 00:00:00|61.0|120.0
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193 t.create, t.info
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196 Sören Gebbert, Thünen Institute of Climate-Smart Agriculture
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199 Available at: t.sample source code (history)
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201 Main index | Temporal index | Topics index | Keywords index | Graphical
202 index | Full index
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204 © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
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208GRASS 7.8.5 t.sample(1)