Geo::H3 - H3 Geospatial Hexagon Indexing System
use Geo::H3;
my $gh3 = Geo::H3->new;
my $hex = $gh3->h3(uint64 => $int); #isa Geo::H3::Index
my $hex = $gh3->h3(string => $string); #isa Geo::H3::Index
my $geo = $gh3->geo(lat=>$lat, lon=>$lon); #isa Geo::H3::Geo
my $hex = $geo->h3($resolution); #isa Geo::H3::Index
my $center = $h3->center; #isa Geo::H3::GeoCoord
my $lat = $center->lat; #isa Double WGS-84 Decimal Degrees
my $lon = $center->lon; #isa Double WGS-84 Decimal Degrees
my $distance = $center->distance($geo); #isa Double meters
This Perl distribution provides a Perl Object Oriented interface to the H3 Core Library. It accesses the H3 C library using libffi and FFI::Platypus.
H3 is a geospatial indexing system that partitions the world into hexagonal cells. Please note that a very few number of cells are pentagons but we use the terms hex or hexagon to include pentagons.
The H3 Core Library implements the H3 grid system. It includes functions for converting from latitude and longitude coordinates to the containing H3 cell, finding the center of H3 cells, finding the boundary geometry of H3 cells, finding neighbors of H3 cells, and more.
The H3 Core Library can be installed from Uber's H3 repository on GitHub https://github.com/uber/h3 which is well documented at https://h3geo.org/docs/.
The Geo::H3 lib is an Object Oriented wrapper on top of the Geo::H3::FFI library. Geo::H3 was written as a wrapper so that in the future we are able to re-write against different backends such as the yet to be developed Geo::H3::XS backend.
- Latitude and longitude cordinates are in radians WGS-84
- H3 Index values are handled as uint64 integers
- GeoCoord values are handled as C structures with lat and lon
- GeoBoundary values are handled as C structures with num_verts and verts
- Latitude and Longitude cordinates are in radians WGS-84
- H3 Index values are handled as uint64 integers
- GeoCoord values are handled as Geo::H3::FFI::Struct::GeoCoord objects
- GeoBoundary values are handled as Geo::H3::FFI::Struct::GeoBoundary objects
- Latitude and longitue cordinates are in decimal degrees WGS-84
- H3 Index values are handled as Geo::H3::Index objects
- GeoCoord values are handled as Geo::H3::GeoCoord objects
- GeoBoundary values are handled as Geo::H3::GeoBoundary objects
Returns a Geo::H3::Index object
my $hex = $gh3->h3(unit64 => $int); #isa Geo::H3::Index
my $hex = $gh3->h3(string => $string); #isa Geo::H3::Index
my $hex = Geo::H3::Index->new(uint64 => $h3_uint64); #isa Geo::H3::Index
my $hex = Geo::H3::Index->new(string => $h3_string); #isa Geo::H3::Index
Returns a Geo::H3::Geo object
my $geo = $gh3->geo(lat=>$lat_deg, lon=>$lon_deg); #isa Geo::H3::Geo
my $geo = Geo::H3::Geo->new(lat=>$lat_deg, lon=>$lon_deg); #isa Geo::H3::Geo
Returns the Geo::H3::FFI object.
This package uses the naming convention of version 3.x of the Uber H3 library. The organization that maintains the open source Uber H3 library has not maintained backward compatibility in version 4.x. This Perl distribution currently sees no reason to support the 4.x version of the Uber H3 library as the 3.7.2 release is stable and full featured.
https://h3geo.org/docs/3.x/, https://github.com/uber/h3/tree/stable-3.x, Geo::H3::FFI
Michael R. Davis
MIT License
Copyright (c) 2021 Michael R. Davis
Geo::H3::Index - H3 Geospatial Hexagon Indexing System Index Object
use Geo::H3::Index;
my $h3 = Geo::H3::Index->new(string => $string); #isa Geo::H3::Index
my $center = $h3->geo; #isa Geo::H3::Geo
my $lat = $center->lat; #isa double WGS-84 Decimal Degrees
my $lon = $center->lon; #isa double WGS-84 Decimal Degrees
my $boundary = $h3->geoBoundary; #isa Geo::H3::GeoBoundary
H3 Geospatial Hexagon Indexing System Index Object provides the primary interface for working with H3 Indexes.
my $h3 = Geo::H3::Index->new(string=>$string);
my $h3 = Geo::H3::Index->new(uint64=>$uint64);
Returns the H3 string representation.
Returns the H3 uint64 representation.
Returns the H3 uint64 representation.
Please note that `index()` was difficult to remember consistently. Therefore, I plan to move to the `uint64()` property moving forward while maintaining backwards compatibility.
Returns the resolution of the hex.
Returns the base cell number of the hex.
Returns non-zero if this is a valid H3 hex.
Returns non-zero if this hex has a resolution with Class III orientation.
Returns non-zero if this hex represents a pentagonal cell.
Returns the maximum number of icosahedron faces the given H3 hex may intersect.
Returns the area in square meters of this hex.
Returns the average area in square meters of hexes at this resolution.
Returns the exact edge length in meters that this hex shares with the passed in neighbor.
my $edgeLength_meters = $hex->edgeLength(); #default hex is first kring neighbor
my $edgeLength_meters = $hex->edgeLength($neighbor_hex_obj);
Returns the average of the exact edge lengths in meters of this hex.
Returns the average edge length in meters of hexes at this resolution.
Returns the centroid of the hex as a Geo::H3::Geo object.
Returns the boundary of the hex as a Geo::H3::GeoBoundary object
Returns a parent hex of this hex as a Geo::H3::Index object.
my $parent = $h3->parent; #next larger resolution
my $parent = $h3->parent(1); #isa Geo::H3::Index
Returns the children of the hex as an array reference of Geo::H3::Index objects.
my $children = $h3->children(12); #isa ARRAY
my $children = $h3->children; #next smaller resolution
Returns the center child (finer) hex contained by this hex at given resolution.
my $centerChild = $hex->centerChild; #isa Geo::H3::Index
my $centerChild = $hex->centerChild(12); #isa Geo::H3::Index
Returns k-rings hexes within k distance of the origin hex.
my $hexes_aref = $hex->kRing($k); #isa ARRAY of L<Geo::H3::Index> objects
Returns a hash reference where the keys are the H3 hex and values are the k distance for the given hex and k value.
my $distances_aref = $hex->kRingDistances($k); #isa ARRAY-ARRAY [ [$hex1, $dist1], [$hex2, $dist2], ... [$hexN, $distN] ]
Returns an array reference of hexes within k distance of the hex object. k-ring 0 is defined as the origin index, k-ring 1 is defined as k-ring 0 and all neighboring indexes, and so on.
my $hexes_aref = $hex->hexRange($k);
Returns a hash reference where the keys are the H3 uint64 and values are the k distance for the given hex and k value.
my $hash = $hex->hexRangeDistances($k); #isa ARRAY-ARRAY [ [$hex1, $dist1], [$hex2, $dist2], ... [$hexN, $distN] ]
Returns the hex ring of this hex as an array reference of Geo::H3::Index objects
my $hexes = $h3->hexRing; #default k = 1
my $hexes = $h3->hexRing(5); #isa ARRAY
Returns a 1 or 0 based on whether or not the provided hex object is a neighbor.
my $areNeighbors = $start_hex->areNeighbors($end_hex);
Returns the hexes starting at this hex to the given end hex as array reference of Geo::H3::Index objects.
my $list_aref = $start_hex_obj->line($end_hex_obj);
Returns the distance in grid cells between this hex to the given end hex.
my $distance = $start_hex_obj->distance($end_hex_obj);
Michael R. Davis
MIT License
Copyright (c) 2021 Michael R. Davis
Geo::H3::Geo - H3 Geospatial Hexagon Indexing System Geo Object
use Geo::H3::Geo;
my $geo = Geo::H3::Geo->new(lat=>$lat, lon=>$lon); #isa Geo::H3::Geo
my $h3 = $geo->h3($resolution); #isa Geo::H3::Index
my $center = $h3->geo; #isa Geo::H3::Geo
my $lat = $center->lat; #isa double WGS-84 Decimal Degrees
my $lon = $center->lon; #isa double WGS-84 Decimal Degrees
H3 Geospatial Hexagon Indexing System Geo Object exposes the lat and lon properties as WGS-84 Decimal Degrees and converts coordinates to radians in the struct method for passing into theGeo::H3::FFI API as a Geo::H3::FFI::Struct::GeoCoord object.
The methods h3 and distance are wrappers around select Geo::H3::FFI methods.
my $geo = Geo::H3::Geo->new(lat => $lat, lon => $lon);
Returns the latitude in decimal degrees WGS-84
Returns the longitude in decimal degrees WGS-84
Returns the Geo object as an FFI::C struct in the Geo::H3::FFI::Struct::GeoCoord namespace for use in the Geo::H3::FFI API.
Indexes the location at the specified resolution, returning the hex object Geo::H3::Index of the cell containing the location.
my $h3 = $geo->h3; #default resolution is 0
my $h3 = $geo->h3(7); #isa Geo::H3::H3Index
Returns undef on error.
Returns in meters the "great circle" or "haversine" distance between pairs of points (lat/lon pairs).
my $distance = $geoA->distance($geoB); #isa Double
Geo::H3, Geo::H3::FFI, Geo::H3::Index, Geo::H3::FFI::Struct::GeoCoord
Michael R. Davis
MIT License
Copyright (c) 2021 Michael R. Davis
Geo::H3::GeoBoundary - H3 Geospatial Hexagon Indexing System GeoBoundary Object
use Geo::H3::GeoBoundary;
my $GeoBoundary = Geo::H3::GeoBoundary->new(gb=>$gb); #isa Geo::H3::GeoBoundary
my $GeoBoundary = Geo::H3::GeoBoundary->new(gb=>$gb, ffi=>$ffi); #isa Geo::H3::GeoBoundary
H3 Geospatial Hexagon Indexing System GeoBoundary Object provides coordinates method to extract data from the FFI GeoBoundary object
my $GeoBoundary = Geo::H3::GeoBoundary->new(gb=>$gb);
Returns the H3 GeoBoundary Object from the API as a Geo::H3::FFI::Struct::GeoBoundary object
my $struct = $GeoBoundary->gb; #isa Geo::H3::FFI::Struct::GeoBoundary
Returns an OGC compatible closed polygon as an array reference of hashes i.e. [{lat=>$lat, lon=>$lon}, ...].
This coordinates format plugs directly into the format required for many Geo::GoogleEarth::Pluggable objects.
Geo::H3, Geo::H3::FFI::Struct::GeoBoundary, Geo::GoogleEarth::Pluggable
Michael R. Davis
MIT License
Copyright (c) 2021 Michael R. Davis
perl-Geo-H3-geo-to-googleearth.pl - Creates a Google Earth document from Coordinates, H3, Parent, Children and Hex Ring.
perl-Geo-H3-geo-to-googleearth.pl --lat=[degrees] --lon=[degrees] --resolution=[hex_resolution] --output=[output_filename]
Default creates output.kmz
$ perl-Geo-H3-geo-to-googleearth.pl
Lat: 38.8894806546995
Lon: -77.0352387595358
Resolution: 8
Output: output.kmz
Format: kmz
KMZ output with defaults specified
$ perl-Geo-H3-geo-to-googleearth.pl --lat=38.889480654699476 --lon=-77.03523875953579 --resolution=8 --output=output.kmz
Lat: 38.889480654699476
Lon: -77.03523875953579
Resolution: 8
Output: output.kmz
Format: kmz
KML output pass a file name with "kml" extension.
$ perl-Geo-H3-geo-to-googleearth.pl --output=output.kml
Lat: 38.8894806546995
Lon: -77.0352387595358
Resolution: 8
Output: output.kml
Format: kml
Geo::GoogleEarth::Pluggable, Geo::GoogleEarth::Pluggable::Plugin::Styles, Path::Class
MIT License
Copyright (c) 2026 Michael R. Davis