1Geo::ShapeFile::Shape(3U)ser Contributed Perl DocumentatiGoeno::ShapeFile::Shape(3)
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6 Geo::ShapeFile::Shape - Geo::ShapeFile utility class.
7
9 use Geo::ShapeFile::Shape;
10 my $shape = Geo::ShapeFile::Shape->new;
12 $shape->parse_shp($shape_data);
13
15 This is a utility class for Geo::ShapeFile that represents shapes.
16
18 This is the Geo::ShapeFile utility class that actually contains shape
19 data for an individual shape from the shp file.
20 EXPORT
22 None by default.
23
25 new()
26 Creates a new Geo::ShapeFile::Shape object, takes no arguments and
27 returns the created object. Normally Geo::ShapeFile does this for
28 you when you call its get_shp_record() method, so you shouldn't
29 need to create a new object. (Eventually this module will have
30 support for _creating_ shapefiles rather than just reading them,
31 then this method will become important.
32 num_parts()
34 Returns the number of parts that make up this shape.
35 num_points()
37 Returns the number of points that make up this shape.
38 points()
40 Returns an array of Geo::ShapeFile::Point objects that contains all
41 the points in this shape. Note that because a shape can contain
42 multiple segments, which may not be directly connected, you
43 probably don't want to use this to retrieve points which you are
44 going to plot. If you are going to draw the shape, you probably
45 want to use get_part() to retrieve the individual parts instead.
46 get_part($part_index);
48 Returns the specified part of the shape. This is the information
49 you want if you intend to draw the shape. You can iterate through
50 all the parts that make up a shape like this:
51 for(1 .. $obj->num_parts) {
53 my $part = $obj->get_part($_);
54 # ... do something here, draw a map maybe
55 }
56 shape_type()
58 Returns the numeric type of this shape, use Geo::ShapeFile::type()
59 to determine the human-readable name from this type.
60 shape_id()
62 Returns the id number for this shape, as contained in the shp file.
63 x_min() x_max() y_min() y_max()
65 z_min() z_max() m_min() m_max()
66 Returns the minimum/maximum ranges of the X, Y, Z, or M values for
67 this shape, as contained in it's header information.
68 has_point($point)
70 Returns true if the point object provided matches one of the points
71 in the shape. Note that this does a simple comparison with the
72 points that make up the shape, it will not find a point that falls
73 along a vertex between two points in the shape. See the
74 Geo::ShapeFile::Point documentation for a note about how to exclude
75 Z and/or M data from being considered when matching points.
76 contains_point($point); =item contains_point($point, $use_index);
78 Returns true if the specified point falls in the interior of this
79 shape and false if the point is outside the shape. Return value is
80 unspecified if the point is one of the vertices or lies on some
81 segment of the bounding polygon.
82 Passing $use_index uses a spatial index if defined (building it if
84 needed). See build_spatial_index for more details. This will be
85 the default behaviour in a future release.
86 Note that the algorithm uses a sidedness algorithm ignoring Z and M
88 fields and so will likely not work if the point is contained within
89 a shape winding the wrong way. Polygon shapes should be
90 anticlockwise for outer boundaries, and clockwise for inner void
91 polygons.
92 build_spatial_index ($index_res)
94 Builds a spatial index for use in contains_point(). $index_res is
95 a positive integer which sets the nnumber of along the y-axis. A
96 value of 0 lets the system determine the number.
97 get_spatial_index()
99 Gets the spatial index. This is a hash indexed by part number.
100 Returns a hash reference in scalar context.
101 bounds
103 Returns the object's bounds as an array (x_min, y_min, x_max,
104 y_max). Returns an array ref in scalar context.
105 get_segments($part)
107 Returns an array consisting of array hashes, which contain the
108 points for each segment of a multi-segment part.
109 vertex_centroid( $part );
111 Returns a Geo::ShapeFile::Point that represents the calculated
112 centroid of the shapes vertices. If given a part index, calculates
113 just for that part, otherwise calculates it for the entire shape.
114 See "centroid" for more on vertex_centroid vs area_centroid.
115 area_centroid( $part );
117 Returns a Geo::ShapeFile::Point that represents the calculated area
118 centroid of the shape. If given a part index, calculates just for
119 that part, otherwise calculates it for the entire shape. See
120 "centroid" for more on vertex_centroid vs area_centroid.
121 centroid($part)
123 For backwards-compatibility reasons, centroid() is currently an
124 alias to vertex_centroid(), although it would probably make more
125 sense for it to point to area_centroid(). To avoid confusion (and
126 possible future deprecation), you should avoid this and use either
127 vertex_centroid or area_centroid.
128 dump()
130 Returns a text dump of the object, showing the shape type, id
131 number, number of parts, number of total points, the bounds for the
132 X, Y, Z, and M ranges, and the coordinates of the points in each
133 part of the shape.
134
136 Please send any bugs, suggestions, or feature requests to
137 <https://github.com/shawnlaffan/Geo-ShapeFile/issues>.
138
140 Geo::ShapeFile
141
143 Jason Kohles, <email@jasonkohles.com>
144 Shawn Laffan, <shawnlaffan@gmail.com>
146
148 Copyright 2002-2013 by Jason Kohles
149 Copyright 2014 by Shawn Laffan
151 This library is free software; you can redistribute it and/or modify it
153 under the same terms as Perl itself.
154perl v5.34.0 2022-01-21 Geo::ShapeFile::Shape(3)