Geo::Line - a sequence of connected points
Geo::Line is a Geo::Shape Geo::Line is a Math::Polygon
my $line = Geo::Line->new(points => [$p1, $p2]); my $line = Geo::Line->line($p1, $p2); my $ring = Geo::Line->ring($p1, $p2, $p3, $p1); my $ring = Geo::Line->ring($p1, $p2, $p3); my $plane = Geo::Line->filled($p1, $p2, $p3, $p1); my $plane = Geo::Line->filled($p1, $p2, $p3);
A 2-dimensional sequence of connected points. The points will be forced to use the same projection.
Create a square from the STRING. The coordinates can be separated by a comma (preferrably), or blanks. When the coordinates end on NSEW, the order does not matter, otherwise lat-long or xy order is presumed.
This routine is very smart. It understands PROJLABEL: <4 coordinates in any order, but with NSEW> ...
example: bbox from string
my $x = '5n 2n 3e e12'; # coordinates in any order my $x = '5e , 2n, 3n, e12'; # coordinates in any order my $x = '2.12-23.1E, N1-4'; # stretches my $x = 'wgs84: 2-5e, 1-8n'; # starts with projection my $x = 'wgs84: e2d12' -3d, n1, n7d12'34"'; my ($xmin, $ymin, $xmax, $ymax, $proj) = Geo::Line->bboxFromString($x); my $p = Geo::Line->ringFromString($x); # When parsing user applications, you probably want: my $p = eval { Geo::Line->bboxFromString($x) }; warn $@ if $@;
The POINTS form a ring() and the filled is part of the geometrical shape.
construct a line, which will probably not have the same begin and end point. The POINTS are passed as new(points), and the other OPTIONS are passed to new() as well.
When called as instance method, the projection, ring, and filled attributes are taken from the initiator, like a clone with modification.
-Option --Defined in --Default bbox Math::Polygon undef clockwise Math::Polygon undef filled <false> points <data> proj Geo::Shape see Geo::Proj::defaultProjection() ring <false>
Implies ring. The filled of the ring is included in the geometrical shape.
With this option, you can specify either Geo::Point objects, or coordinate pairs which will get transformed into such objects. WARNING: in that case, the coordinates must be in xy order.
The first point is the last point. When specified, you have to make sure that this is the case. If ring() is used to create this object, that routine will check/repair it for you.
example:
my $point = Geo::Point->xy(1, 2); my $line = Geo::Line->new ( points => [$point, [3,4], [5,6], $point] , ring => 1 )'
The first and last point will be made the same: if not yet, than a reference to the first point is appended to the list. A "ring" does not cover the internal.
Calls bboxFromString() and then produces a ring object from than. Don't forget the eval when you call this method.
eval
Returns the Geo::Point for the point with the specified INDEX or indices.
In LIST context, this returns all points as separate scalars: each is a Geo::Point with projection information. In SCALAR context, a reference to the coordinates is returned.
With points(), you get arrays with XY coordinates returned, but without the projection information. That will be much faster, but not sufficient for some uses.
Returns a true value is the internals of the ring of points are declared to belong to the shape.
Returns a true value if the sequence of points are a ring or filled: the first point is the last.
See "Attributes" in Math::Polygon
See "Attributes" in Geo::Shape
See "Projections" in Geo::Shape
Returns the area enclosed by the polygon. Only useful when the points are in some orthogonal projection.
The bounding box coordinates. These are more useful for rings than for open line pieces.
See "Geometry" in Geo::Shape
See "Geometry" in Math::Polygon
Clip the shape to the bounding box of OBJECT, or the boxing parameters specified. A list of Geo::Line objects is returned if anything is inside the object.
On the moment Math::Polygon::lineClip() and Math::Polygon::fillClip1() are used to do the job. In the future, that may change.
The length of the line, only useful in a orthogonal coordinate system (projection). See also perimeter().
The length of the line on the ring. A check is performed that the ring is closed, but further this returns the result of length()
See "Transformations" in Math::Polygon
See "Clipping" in Math::Polygon
See "Display" in Geo::Shape
Returns a string representation of the line, which is also used for stringification.
See "OVERLOAD" in Geo::Shape
If you think you have a ring of points (a polygon), than do specify that when that object is instantiated (ring() or new(ring)).
Only a subset of all objects can be used in the distance calculation. The limitation is purely caused by lack of time to implement this.
This module is part of Geo-Point distribution version 0.94, built on December 21, 2012. Website: http://perl.overmeer.net/geo/ All modules in this suite: "Geo::Point", "Geo::Proj4", "Geo::WKT", "Math::Polygon", "Geo::GML", "Geo::ISO19139", "Geo::EOP", "Geo::Format::Envisat", and "Geo::Format::Landsat".
Please post questions or ideas to the mailinglist at http://geo-perl@list.hut.fi
Copyrights 2005-2012 by [Mark Overmeer]. For other contributors see ChangeLog.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See http://www.perl.com/perl/misc/Artistic.html
To install Geo::Point, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Geo::Point
CPAN shell
perl -MCPAN -e shell install Geo::Point
For more information on module installation, please visit the detailed CPAN module installation guide.