DX::Grid

The DX::Grid module provides methods for converting between lat/long coordinate pairs and amateur radio Maidenhead grid locators. It can also validate the format of a grid string.

The supported grid formats are 4-character (e.g. FN22) and 6-character (e.g. FN32ab).

The range of grids is from AA00aa to RR99xx.

You can learn more about grid squares from the ARRL.

Installation

Add this line to your application's Gemfile:

gem 'dx-grid'

And then execute:

$ bundle

Or install it yourself as:

$ gem install dx-grid

Usage

require 'dx/grid'

Decoding a Grid to a Coordinate

DX::Grid.decode('FN22') # => [42.5, -75.0]
DX::Grid.decode('FN22ab') # => [42.0625, -75.95833333333333]

Encoding a Coordinate to a Grid

DX::Grid.encode([42.481076, -75.037847]) # => 'FN22'
DX::Grid.encode([42.481076, -75.037847], :length => 4) # => 'FN22'
DX::Grid.encode([42.481076, -75.037847], :length => 6) # => 'FN22cd'

Validating a Grid

DX::Grid.valid?('FN22') # => true
DX::Grid.valid?('fn22') # => true
DX::Grid.valid?('AA00aa') # => true
DX::Grid.valid?('ab12xx') # => true
DX::Grid.valid?('MO00OO') # => true
DX::Grid.valid?('lo00ol') # => true

DX::Grid.valid?('FN') # => false
DX::Grid.valid?('st12') # => false
DX::Grid.valid?('fn22yz') # => false
DX::Grid.valid?('hello world') # => false
DX::Grid.valid?(nil) # => false
DX::Grid.valid?('') # => false
DX::Grid.valid?(5) # => false
DX::Grid.valid?(Math::PI) # => false

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/schrockwell/dx-grid.

License

The gem is available as open source under the terms of the MIT License.