Module: OpenLocationCode

Defined in:
lib/open_location_code.rb,
lib/open_location_code/decoder.rb,
lib/open_location_code/encoder.rb,
lib/open_location_code/version.rb,
lib/open_location_code/code_area.rb

Overview

Example:

# Encode a location, default accuracy:
code = OpenLocationCode.encode(47.365590, 8.524997) # 8FVC9G8F+6X

# Encode a location using one stage of additional refinement:
code = OpenLocationCode.encode(47.365590, 8.524997, 11) # 8FVC9G8F+6XQ

# Decode a full code:
coord = OpenLocationCode.decode(code)

Defined Under Namespace

Classes: CodeArea, Decoder, Encoder

Constant Summary collapse

SEPARATOR =

A separator used to break the code into two parts to aid memorability

'+'
SEPARATOR_POSITION =

The number of characters to place before the separator.

8
PADDING_CHARACTER =

The character used to pad codes.

'0'
CODE_ALPHABET =

The character set used to encode the values.

'23456789CFGHJMPQRVWX'
ENCODING_BASE =

The base to use to convert numbers to/from.

CODE_ALPHABET.length
LATITUDE_MAX =

The maximum value for latitude in degrees.

90
LONGITUDE_MAX =

The maximum value for longitude in degrees.

180
PAIR_CODE_LENGTH =

Maxiumum code length using lat/lng pair encoding. The area of such a code is approximately 13x13 meters (at the equator), and should be suitable for identifying buildings. This excludes prefix and separator characters.

10
PAIR_RESOLUTIONS =

The resolution values in degrees for each position in the lat/lng pair encoding. These give the place value of each position, and therefore the dimensions of the resulting area.

[20.0, 1.0, 0.05, 0.0025, 0.000125]
GRID_COLUMNS =

Number of columns in the grid refinement method.

4
GRID_ROWS =

Number of rows in the grid refinement method.

5
GRID_SIZE_DEGREES =

Size of the initial grid in degrees.

0.000125
MIN_TRIMMABLE_CODE_LEN =

Minimum length of a code that can be shortened.

6
OLCError =

Error class

Class.new(StandardError)
VERSION =

Version of lib

"0.1.0"

Class Method Summary collapse

Class Method Details

.alphabet ⇒ String

OLC alphabet.

Returns:

  • (String) 


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# File 'lib/open_location_code.rb', line 70

def self.alphabet
  CODE_ALPHABET
end

.decode(code) ⇒ CodeArea

Decodes an Open Location Code into the location coordinates.

Parameters:

  • code (String) —

    The Open Location Code to decode.

Returns:

  • (CodeArea) —

    An object that provides the latitude and longitude of two of the corners of the area, the center, and the length of the original code.



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# File 'lib/open_location_code.rb', line 105

def self.decode(code)
  Decoder.new(code).process
end

.encode(latitude, longitude, code_length = nil) ⇒ String

Encode a location into an Open Location Code.

Produces a code of the specified length, or the default length if no length
is provided.

The length determines the accuracy of the code. The default length is
10 characters, returning a code of approximately 13.5x13.5 meters. Longer
codes represent smaller areas, but lengths > 14 are sub-centimetre and so
11 or 12 are probably the limit of useful codes.

Parameters:

  • latitude (Float) —

    A latitude in signed decimal degrees. Will be clipped to the range -90 to 90.

  • longitude (Float) —

    A longitude in signed decimal degrees. Will be normalised to the range -180 to 180.

  • code_length (Integer) (defaults to: nil) —

    The number of significant digits in the output code, not including any separator characters.

Returns:

  • (String) —

    Encoded code



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# File 'lib/open_location_code.rb', line 93

def self.encode(latitude, longitude, code_length = nil)
  Encoder.new(latitude, longitude, code_length || PAIR_CODE_LENGTH).process
end