Class: TspRunner::Location

Inherits:
Object
  • Object
show all
Defined in:
lib/tsp_runner/location.rb

Constant Summary collapse

RADIANS_PER_DEGREE = 
Math::PI / 180
EARTH_RADIUS =

in meters

6371 * 1000

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, lat, lon) ⇒ Location

Returns a new instance of Location.

Parameters:

  • name (String) —

    the name of the location

  • lat (Fixnum) —

    the latitude

  • lon (Fixnum) —

    the longitude



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# File 'lib/tsp_runner/location.rb', line 11

def initialize(name, lat, lon)
  unless lat.in?(-90..90)
    raise ArgumentError, 'Latitudue should be between -90 and 90'
  end

  unless lon.in?(-180..180)
    raise ArgumentError, 'Longitudue should be between -180 and 180'
  end

  @name, @lat, @lon = name, lat, lon
end

Instance Attribute Details

#lat ⇒ Object (readonly)

Returns the value of attribute lat.



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# File 'lib/tsp_runner/location.rb', line 6

def lat
  @lat
end

#lon ⇒ Object (readonly)

Returns the value of attribute lon.



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# File 'lib/tsp_runner/location.rb', line 6

def lon
  @lon
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/tsp_runner/location.rb', line 6

def name
  @name
end

Instance Method Details

#distance_from(location) ⇒ Fixnum

Gleefully stolen from: stackoverflow.com/questions/12966638/how-to-calculate-the-distance-between-two-gps-coordinates-without-using-google-m

Returns:

  • (Fixnum) —

    the Haversine distance of the location (from self) as measured in meters



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# File 'lib/tsp_runner/location.rb', line 38

def distance_from(location)
  delta_lat = location.lat_rad - lat_rad
  delta_lon = location.lon_rad - lon_rad

  a = Math.sin(delta_lat / 2) ** 2 + Math.cos(lat_rad) *
      Math.cos(location.lat_rad) * Math.sin(delta_lon / 2) ** 2
  c = 2 * Math::atan2(Math::sqrt(a), Math::sqrt(1 - a))

  EARTH_RADIUS * c
end

#lat_rad ⇒ Fixnum

Returns the latitude in radians.

Returns:

  • (Fixnum) —

    the latitude in radians



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# File 'lib/tsp_runner/location.rb', line 24

def lat_rad
  lat * RADIANS_PER_DEGREE
end

#lon_rad ⇒ Fixnum

Returns the longitude in radians.

Returns:

  • (Fixnum) —

    the longitude in radians



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# File 'lib/tsp_runner/location.rb', line 29

def lon_rad
  lon * RADIANS_PER_DEGREE
end