Class: GPX::TrackPoint

Inherits:
Point show all
Defined in:
lib/gpx/track_point.rb

Overview

Basically the same as a point, the TrackPoint class is supposed to represent the points that are children of Segment elements. So, the only real difference is that TrackPoints hold a reference to their parent Segments.

Constant Summary collapse

RADIUS =

earth’s mean radius in km

6371

Constants inherited from Point

Point::D_TO_R

Instance Attribute Summary collapse

Attributes inherited from Point

#elevation, #extensions, #gpx_file, #lat, #lon, #speed, #time

Instance Method Summary collapse

Methods inherited from Point

#lat_lon, #latr, #lon_lat, #lonr

Methods inherited from Base

#instantiate_with_text_elements

Constructor Details

#initialize(opts = {}) ⇒ TrackPoint

Returns a new instance of TrackPoint.



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# File 'lib/gpx/track_point.rb', line 11

def initialize(opts = {})
  super(opts)
  @segment = opts[:segment]
end

Instance Attribute Details

#segment ⇒ Object

Returns the value of attribute segment.



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# File 'lib/gpx/track_point.rb', line 9

def segment
  @segment
end

Instance Method Details

#haversine_distance_from(p2) ⇒ Object

Units are in km



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# File 'lib/gpx/track_point.rb', line 17

def haversine_distance_from(p2)
  d_lat = p2.latr - latr
  d_lon = p2.lonr - lonr
  a = Math.sin(d_lat / 2) * Math.sin(d_lat / 2) + Math.cos(latr) * Math.cos(p2.latr) * Math.sin(d_lon / 2) * Math.sin(d_lon / 2)
  c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a))
  RADIUS * c
end

#law_of_cosines_distance_from(p2) ⇒ Object

Units are in km



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# File 'lib/gpx/track_point.rb', line 26

def law_of_cosines_distance_from(p2)
  Math.acos(Math.sin(latr) * Math.sin(p2.latr) + Math.cos(latr) * Math.cos(p2.latr) * Math.cos(p2.lonr - lonr)) * RADIUS
end