Geo::Shape - base class for 2-dimensional points on the earth surface
Geo::Shape is extended by Geo::Line Geo::Point Geo::Space Geo::Surface
use Geo::Shape; my $p1 = Geo::Point->new(lat => 2.17, ...); my $p2 = Geo::Point->latlong(2.17, 3.14); # wgs84 is default my $p3 = $p1->in('wgs84'); # conversion my $p4 = $p1->in('utm'); # conversion
Base class for the many geo-spatial objects defined by the GeoPoint distribution.
Geo::Shape->new(OPTIONS)
Create a new object.
Option--Default proj see Geo::Proj::defaultProjection()
. proj => LABEL
$obj->proj
Returns the nickname of the projection used by the component. Be warned: this is not a Geo::Point object, but just a label.
$obj->proj4
Returns the proj4 object which handles the projection.
$obj->in(LABEL|'utm')
The coordinates of this point in a certain projection, refered to with the LABEL. The projection is defined with new(). When simply 'utm' is provided, the best UTM zone is selected.
In LIST context, the coordinates are returned. In SCALAR context, a new object is returned.
example:
my $gp = Geo::Point->latlong(1,2); # implicit conversion to wgs84, if not already in latlong my ($lat, $long) = $pr->latlong; # will select an utm zone for you my $p_utm = $gp->in('utm'); my ($x, $y) = $p_utm->xy; my $label = $p_utm->proj; my ($datum, $zone) = $label =~ m/^utm-(\w+)-(\d+)$/;
$obj->projectOn(NICK, POINTS)
The POINTS are ARRAYS with each an X and Y coordinate of a single point in space. A list of transformed POINTS is returned, which is empty if no change is needed. The returned list is preceeded by a projection NICK which is the result, usually the same as the provided NICK, but in some cases (for instance UTM) it may be different.
$obj->area
Returns the area covered by the geo structure. Points will return zero.
$obj->bbox
Returns the bounding box of the object as four coordinates, respectively xmin, ymin, xmax, ymax. The values are expressed in the coordinate system of the object.
$obj->bboxCenter
Returns a Geo::Point which represent the middle of the object. It is the center of the bounding box. The values is cached, once computed.
Be warned that the central point in one projection system may be quite different from the central point in some other projectionsystem .
$obj->bboxRing([XMIN, YMIN, XMAX, YMAX, [PROJ]])
Geo::Shape->bboxRing([XMIN, YMIN, XMAX, YMAX, [PROJ]])
Returns a Geo::Line which describes the outer bounds of the object called upon, counter-clockwise and left-bottom first. As class method, you need to specify the limits and the PROJection.
$obj->distance(OBJECT, [UNIT])
Calculate the distance between this object and some other object. For many combinations of objects this is not supported or only partially supported.
This calculation is performed with Geo::Distance in accurate mode. The default UNIT is kilometers. Other units are provided in the manual page of Geo::Distance. As extra unit, degrees and radians are added as well as the km alias for kilometer.
degrees
radians
km
$obj->perimeter
Returns the length of the outer border of the object's components. For points, this returns zero.
$obj->deg2dm(DEGREES, POS, NEG)
Geo::Shape->deg2dm(DEGREES, POS, NEG)
Like deg2dms() but without showing seconds.
print $point->deg2dm(0.12, 'e', 'w'); print Geo::Shape->deg2dm(0.12, 'e', 'w');
$obj->deg2dms(DEGREES, POS, NEG)
Geo::Shape->deg2dms(DEGREES, POS, NEG)
print $point->deg2dms(0.12, 'e', 'w'); print Geo::Shape->deg2dms(0.12, 'e', 'w');
$obj->dms2deg(DMS)
Geo::Shape->dms2deg(DMS)
Accepts for instance 3d12'24.123, 3d12"E, 3.12314w, n2.14, s3d12", -12d34, and returns floating point degrees.
Error: distance calculation not implemented between a $kind and a $kind
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.
Error: in() not implemented for a $class
This module is part of Geo-Point distribution version 0.93, built on May 19, 2010. 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 2005-2010 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.