Class: GeoRuby::SimpleFeatures::LineString

Inherits:
Object
  • Object
show all
Defined in:
lib/georuby-ext/georuby/line_string.rb,
lib/georuby-ext/georuby/locators.rb

Defined Under Namespace

Classes: PointLocator, Segment

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.merge(lines) ⇒ Object 



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# File 'lib/georuby-ext/georuby/line_string.rb', line 19

def self.merge(lines)
  merged_points = lines.map(&:points).flatten.uniq
  if merged_points.size > 1
    from_points merged_points, lines.first.srid, lines.first.with_z, lines.first.with_m
  end
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/georuby-ext/georuby/line_string.rb', line 30

def ==(other)
  other.respond_to?(:points) and points == other.points
end

#change(options) ⇒ Object 



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# File 'lib/georuby-ext/georuby/line_string.rb', line 3

def change(options)
  self.class.from_points(options[:points] || points, 
                         options[:srid] || srid,
                         options[:with_z] || with_z, 
                         options[:with_m] || with_m)
  # or instead of || requires parenthesis
end

#distance ⇒ Object 



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# File 'lib/georuby-ext/georuby/locators.rb', line 96

def distance
  segments.sum(&:distance)
end

#distance_from_line(target) ⇒ Object 



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# File 'lib/georuby-ext/georuby/locators.rb', line 67

def distance_from_line(target)
  nearest_locator(target).distance_from_segment
end

#distance_on_line(target) ⇒ Object 



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# File 'lib/georuby-ext/georuby/locators.rb', line 62

def distance_on_line(target)
  nearest_locator = nearest_locator(target)
  nearest_locator.distance_on_segment + nearest_locator.segment.line_distance_at_departure
end

#interpolate_point(location) ⇒ Object 



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# File 'lib/georuby-ext/georuby/locators.rb', line 100

def interpolate_point(location)
  return points.last if location >= 1
  return points.first if location <= 0

  distance_on_line = location * distance

  segment = segments.find do |segment|
    segment.line_distance_at_arrival > distance_on_line
  end

  location_on_segment =
    (distance_on_line - segment.line_distance_at_departure) / segment.distance

  segment.interpolate_point location_on_segment
end

#locate_point(target) ⇒ Object 



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# File 'lib/georuby-ext/georuby/locators.rb', line 58

def locate_point(target)
  distance_on_line(target) / distance
end

#locators(point) ⇒ Object 



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# File 'lib/georuby-ext/georuby/locators.rb', line 75

def locators(point)
  segments.collect { |segment| segment.locator(point) }
end

#nearest_locator(target) ⇒ Object 



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# File 'lib/georuby-ext/georuby/locators.rb', line 71

def nearest_locator(target)
  locators(target).min_by(&:distance_from_segment)
end

#reverse ⇒ Object 



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# File 'lib/georuby-ext/georuby/line_string.rb', line 11

def reverse
  change :points => points.reverse
end

#segments ⇒ Object 



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# File 'lib/georuby-ext/georuby/locators.rb', line 79

def segments
  previous_point = nil
  distance_from_departure = 0

  points.inject([]) do |segments, point|
    Segment.new(previous_point, point).tap do |segment|
      segment.line = self
      segment.line_distance_at_departure = segments.sum(&:distance)
      
      segments << segment
    end if previous_point
    
    previous_point = point
    segments
  end
end

#to_rgeo ⇒ Object 



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# File 'lib/georuby-ext/georuby/line_string.rb', line 26

def to_rgeo
  RGeo::Geos::factory(:srid => srid).line_string(points.collect(&:to_rgeo))
end

#to_ring ⇒ Object 



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# File 'lib/georuby-ext/georuby/line_string.rb', line 36

def to_ring
  ring_points = closed? ? points : points + [first]
  GeoRuby::SimpleFeatures::LinearRing.from_points ring_points, srid, with_z, with_m
end

#to_wgs84 ⇒ Object 



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# File 'lib/georuby-ext/georuby/line_string.rb', line 15

def to_wgs84
  change :points => points.map(&:to_wgs84), :srid => 4326
end