3
<em>v.select</em> allows the user to select features from a vector
4
by features from another one.
8
Only features with category numbers will be considered. If required
9
the <em>v.category</em> module can be used to add them. Typically
10
boundaries do not need to be given a category number, as an area's
11
attributes are inherited from the centroid. Typically points, lines, and
12
centroids will always want to have a cat number.
14
e.g. take a road which separates two farms. It is ambiguous as to which
15
farm an attribute that is attached to the road belongs to. The boundary
16
only needs a cat number if it will hold its own attributes, such as road
17
name or pavement form. A centroid in each paddock holds the information
18
with respect to ownership, area, etc.
23
Extract forest fire points from larger fire map:
25
<div class="code"><pre>
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v.select ainput=fire binput=forest output=forest_fire
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Extract Italian rivers from VMAP0 watercourses map:
32
<div class="code"><pre>
33
v.select ainput=watrcrsl_eurnasia_wgs84 binput=italy_area \
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output=watrcrsl_italy operator=overlap
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<a HREF="v.category.html">v.category</a>,
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<a HREF="v.overlay.html">v.overlay</a>,
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<a HREF="sql.html">GRASS SQL interface</a></em>
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<i>Last changed: $Date: 2008-12-13 18:43:05 +0100 (Sat, 13 Dec 2008) $</i>