Provided by: libgeo-point-perl_0.96-2_all 
NAME
Geo::Shape - base class for 2-dimensional points on the earth surface
INHERITANCE
Geo::Shape is extended by
Geo::Line
Geo::Point
Geo::Space
Geo::Surface
SYNOPSIS
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
DESCRIPTION
Base class for the many geo-spatial objects defined by the GeoPoint distribution.
METHODS
Constructors
Geo::Shape->new(%options)
Create a new object.
-Option--Default
proj see Geo::Proj::defaultProjection()
proj => LABEL
Attributes
$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.
Projections
$obj->in(<$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 preceded
by the projection nick of the result; usually the same as the provided $nick, but in some cases (for
instance UTM) it may differ.
Geometry
$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.
$obj->perimeter()
Returns the length of the outer border of the object's components. For points, this returns zero.
Display
$obj->deg2dm($degrees, $pos, $neg)
Geo::Shape->deg2dm($degrees, $pos, $neg)
Like deg2dms() but without showing seconds.
example:
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)
Translate floating point $degrees into a "degrees minutes seconds" notation. An attempt is made to
handle rounding errors.
example:
print $point->deg2dms(-12.34, 'E', 'W');' # --> 12d20'24"W
print Geo::Shape->deg2dms(52.1234, 'E', 'W'); # --> 52d07'24"E
$obj->dms2deg($dms)
Geo::Shape->dms2deg($dms)
Accepts for instance 3d12'24.123, 3d12"E, 3.12314w, n2.14, s3d12", -12d34, and returns floating point
degrees.
OVERLOAD
overload: '""' (stringification)
Returns a string "$proj($lat,$long)" or "$proj($x,$y)". The $proj is the nickname you have assigned
to the projection.
overload: 'bool' (truth value)
A point is always true: defined.
DIAGNOSTICS
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
SEE ALSO
This module is part of Geo-Point distribution version 0.96, built on January 21, 2014. 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
LICENSE
Copyrights 2005-2014 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