Packages
geo
0.12.0
4.1.0
4.0.1
4.0.0
3.6.0
3.5.1
3.5.0
3.4.3
3.4.2
3.4.1
3.4.0
3.3.8
3.3.7
3.3.5
3.3.4
3.3.3
3.3.2
3.3.1
3.3.0
3.2.0
3.1.0
3.0.0
2.1.0
2.0.0
1.5.0
1.4.1
1.4.0
1.3.1
1.3.0
1.2.1
1.2.0
1.1.2
1.1.1
1.1.0
1.0.6
1.0.5
1.0.4
1.0.3
1.0.2
1.0.1
1.0.0
0.18.0
0.17.0
0.16.1
0.16.0
0.15.2
0.15.1
0.15.0
0.14.0
0.13.0
0.12.0
0.11.2
0.11.1
0.11.0
0.10.1
0.10.0
0.9.3
0.9.2
0.9.1
0.9.0
0.8.0
0.7.2
0.7.1
0.6.1
0.5.1
Encodes and decodes WKB, WKT, and GeoJSON formats.
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README.md
# Geo
A collection of GIS functions. Handles conversions to and from WKT, WKB, and GeoJSON for the following geometries:
* Point
* LineString
* Polygon
* MultiPoint
* MulitLineString
* MultiPolygon
* GeometryCollection
Also includes an encoder, decoder, and formatter for using PostGIS data types with Postgrex
```elixir
defp deps do
[{:geo, "~> 0.12.0"}]
end
```
[Documentation](http://hexdocs.pm/geo)
## Examples
* Encode and decode WKT and EWKT
```elixir
iex(1)> point = Geo.WKT.decode("POINT(30 -90)")
%Geo.Point{ coordinates: {30, -90}, srid: nil}
iex(2)> Geo.WKT.encode(point)
"POINT(30 -90)"
iex(3)> point = Geo.WKT.decode("SRID=4326;POINT(30 -90)")
%Geo.Point{coordinates: {30, -90}, srid: 4326}
```
* Encode and decode WKB and EWKB
```elixir
iex(1)> point = Geo.WKB.decode("0101000000000000000000F03F000000000000F03F")
%Geo.Point{ coordinates: {1.0, 1.0}, srid: nil }
iex(2)> Geo.WKB.encode(point)
"00000000013FF00000000000003FF0000000000000"
iex(3)> point = Geo.WKB.decode("0101000020E61000009EFB613A637B4240CF2C0950D3735EC0")
%Geo.Point{ coordinates: {36.9639657, -121.8097725}, srid: 4326 }
iex(4)> Geo.WKB.encode(point)
"0020000001000010E640427B633A61FB9EC05E73D350092CCF"
```
* Encode and decode GeoJSON
```elixir
iex(1)> point = Geo.JSON.decode("{ \"type\": \"Point\", \"coordinates\": [100.0, 0.0] }")
%Geo.Point{ coordinates: {100.0, 0.0}, srid: nil }
iex(2)> Geo.JSON.encode(point)
"{\"type\":\"Point\",\"coordinates\":[100.0,0.0]}"
```
* A Postgrex Extension for PostGIS data types
```elixir
opts = [hostname: "localhost", username: "postgres", database: "geo_postgrex_test",
encoder: &Geo.PostGIS.encoder/3, decoder: &Geo.PostGIS.decoder/4,
formatter: &Geo.PostGIS.formatter/1 ]
[hostname: "localhost", username: "postgres", database: "geo_postgrex_test",
extensions: [{Geo.PostGIS, library: Geo}]]
{:ok, pid} = Postgrex.Connection.start_link(opts)
{:ok, #PID<0.115.0>}
geo = %Geo.Point{coordinates: {30, -90}, srid: 4326}
%Geo.Point{coordinates: {30, -90}, srid: 4326}
{:ok, _} = Postgrex.Connection.query(pid, "CREATE TABLE point_test (id int, geom geometry(Point, 4326))")
{:ok, %Postgrex.Result{columns: nil, command: :create_table, num_rows: 0, rows: nil}}
{:ok, _} = Postgrex.Connection.query(pid, "INSERT INTO point_test VALUES ($1, $2)", [42, geo])
{:ok, %Postgrex.Result{columns: nil, command: :insert, num_rows: 1, rows: nil}}
Postgrex.Connection.query(pid, "SELECT * FROM point_test")
{:ok, %Postgrex.Result{columns: ["id", "geom"], command: :select, num_rows: 1,
rows: [{42, %Geo.Point{coordinates: {30.0, -90.0}, srid: 4326 }}]}}
```
* Can now be used with Ecto as well
```elixir
#Add extensions to your repo config
config :thanks, Repo,
database: "geo_postgrex_test",
username: "postgres",
password: "postgres",
hostname: "localhost",
adapter: Ecto.Adapters.Postgres,
extensions: [{Geo.PostGIS, library: Geo}]
#Create a model
defmodule Test do
use Ecto.Model
schema "test" do
field :name, :string
field :geom, Geo.Point
end
end
#Geometry columns can be created in migrations too
defmodule Repo.Migrations.Init do
use Ecto.Migration
def up do
create table(:test) do
add :name, :string
add :geom, :geometry
end
end
def down do
drop table(:test)
end
end
```