Geografic-Information-System/temporal/t.vect.export/t.vect.export.html

<h2>DESCRIPTION</h2>

<em>t.vect.export</em> exports a space time vector dataset (stvds)
to a tar archive as either GML (using <em><a href="v.out.ogr.html">v.out.ogr</a></em>)
or GRASS pack files. In addition to the pack or GML files, several
metadata files are also created in the archive that describe the
temporal layout. All time stamps are stored in the file "list.txt",
for each map one row. The name of the map, the start time and the
end time are written. In case of a time instance, the start time is
equal to the end time. The "init.txt" file stores the temporal type,
the number of maps, the chosen export format and some other
metadata. The "proj.txt" file stores the projection information as a
proj4 string of the location the space time vector dataset was
exported from. The file "readme.txt" describes the file format. The
output of v.info for each vector map in the space time dataset is
stored in "metadata.txt".

<p>Gzip or bzip2 (default) compression can be specified with the
<strong>compress</strong> option. Archives exported with
<em><a href="t.vect.export.html">t.vect.export</a></em> can be imported
with <em><a href="t.vect.import.html">t.vect.import</a></em>.

<h2>EXAMPLE</h2>

In this example 5 vector maps are created and
registered in a single space time vector dataset named <em>random_locations</em>.
Each vector map represents random locations
within the boundary of the state taken at 1 month intervals.

<div class="code"><pre>
db.connect -d

for i in `seq 1 5` ; do
    v.random output=map_$i n=500 input=boundary_state@PERMANENT
    echo map_$i >> map_list.txt
done

t.create type=stvds temporaltype=absolute \
         output=random_locations \
         title="Random locations" \
         description="Vector test dataset with random locations"

t.register -i type=vect input=random_locations \
           file=map_list.txt start="2012-01-01" increment="1 months"

t.vect.export input=random_locations output=random_locations.tar

tar xvf random_locations.tar
map_1.xml
map_1.xsd
map_2.xml
map_2.xsd
map_3.xml
map_3.xsd
map_4.xml
map_4.xsd
map_5.xml
map_5.xsd
list.txt
proj.txt
init.txt
readme.txt
metadata.txt

cat init.txt
stds_type=stvds
format=GML
temporal_type=absolute
semantic_type=mean
number_of_maps=5
north=258414.015442
south=185016.401592
east=678328.848292
west=596711.453211

cat proj.txt
+proj=lcc
+lat_1=36.16666666666666
+lat_2=34.33333333333334
+lat_0=33.75
+lon_0=-79
+x_0=609601.22
+y_0=0
+no_defs
+a=6378137
+rf=298.257222101
+towgs84=0.000,0.000,0.000
+to_meter=1

cat list.txt
map_1|2012-01-01 00:00:00|2012-02-01 00:00:00
map_2|2012-02-01 00:00:00|2012-03-01 00:00:00
map_3|2012-03-01 00:00:00|2012-04-01 00:00:00
map_4|2012-04-01 00:00:00|2012-05-01 00:00:00
map_5|2012-05-01 00:00:00|2012-06-01 00:00:00

cat readme.txt
This space time vector dataset was exported with t.vect.export of GRASS GIS 7

Files:
       *.xml  -- Vector GML files
     proj.txt -- Projection information in PROJ.4 format
     init.txt -- GRASS GIS space time vector dataset information
     list.txt -- Time series file, lists all maps by name with interval
                 time stamps in ISO-Format. Field separator is |
 metadata.txt -- The output of t.info
   readme.txt -- This file
</pre></div>


<h2>SEE ALSO</h2>

<em>
<a href="t.vect.import.html">t.vect.import</a>,
<a href="t.create.html">t.create</a>,
<a href="t.info.html">t.info</a>
</em>

<h2>AUTHOR</h2>

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

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