Class: SdbDal::Geo::Location

Inherits:
Object
  • Object
show all
Defined in:
lib/sdb_dal/geo.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(lat, lon) ⇒ Location

Returns a new instance of Location.



11
12
13
14
 
# File 'lib/sdb_dal/geo.rb', line 11

def initialize(lat,lon)
  self.latitude=lat
  self.longitude=lon
end

Instance Attribute Details

#latitude ⇒ Object

Returns the value of attribute latitude.



8
9
10
 
# File 'lib/sdb_dal/geo.rb', line 8

def latitude
  @latitude
end

#longitude ⇒ Object

Returns the value of attribute longitude.



9
10
11
 
# File 'lib/sdb_dal/geo.rb', line 9

def longitude
  @longitude
end

Class Method Details

.acos(rad) ⇒ Object 



136
137
138
 
# File 'lib/sdb_dal/geo.rb', line 136

def self.acos(rad)
  Math.atan2(Math.sqrt(1 - rad**2), rad)
end

.deg2rad(deg) ⇒ Object 



128
129
130
 
# File 'lib/sdb_dal/geo.rb', line 128

def self.deg2rad(deg)
(deg * Math::PI / 180)
end

.rad2deg(rad) ⇒ Object 



132
133
134
 
# File 'lib/sdb_dal/geo.rb', line 132

def self.rad2deg(rad)
  (rad * 180 / Math::PI)
end

.to_location(address) ⇒ Object 



91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
 
# File 'lib/sdb_dal/geo.rb', line 91

def  Location.to_location(address)
  width=90.0
  height=45.0

  index=0
  x=0
  y=0
  length=address.length-1
  length.times do
    index+=1

    puts address[index].chr
    case address[index].chr

       when 'r'
        x+=width
        y+=height
       when 'q'
        x-=width
        y+=height

       when 't'
        x-=width
        y-=height
       when 's'
        x+=width
        y-=height
    end
    width/=2
    height/=2
  end
    loc=Location.new
  loc.latitude=y
  loc.longitude=x
  return loc
end

Instance Method Details

#distance_in_miles(loc2) ⇒ Object 



140
141
142
143
144
145
146
147
148
149
150
 
# File 'lib/sdb_dal/geo.rb', line 140

def distance_in_miles( loc2)
  lat2 = loc2.latitude
  lon2 = loc2.longitude
  theta = self.longitude - lon2
  
  dist = Math.sin(self.deg2rad(self.latitude)) * Math.sin(deg2rad(lat2)) + Math.cos(self.deg2rad(self.latitude)) * Math.cos(self.deg2rad(lat2)) * Math.cos(deg2rad(theta))
  
  dist = self.rad2deg(self.acos(dist))
  
  (dist * 60 * 1.1515).round #distance in miles
end

#get_nearby_addresses(zoom_level) ⇒ Object 



53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
 
# File 'lib/sdb_dal/geo.rb', line 53

def get_nearby_addresses(zoom_level)
  address=self.to_address
  if address.length>(zoom_level+1)
    address=address.slice(0,zoom_level+1)        
  end
  
  result=[address]
  
  tileWidth=360.0/(2**zoom_level)
  tileHeight=180.0/(2**zoom_level)

  other=Geo::Location.new(self.latitude+tileHeight,self.longitude+tileWidth)
  result << other.to_address.slice(0,zoom_level+1)

  other=Geo::Location.new(self.latitude+tileHeight,self.longitude)
  result << other.to_address.slice(0,zoom_level+1)

  other=Geo::Location.new(self.latitude+tileHeight,self.longitude-tileWidth)
  result << other.to_address.slice(0,zoom_level+1)

  other=Geo::Location.new(self.latitude-tileHeight,self.longitude+tileWidth)
  result << other.to_address.slice(0,zoom_level+1)

  other=Geo::Location.new(self.latitude-tileHeight,self.longitude)
  result << other.to_address.slice(0,zoom_level+1)

  other=Geo::Location.new(self.latitude-tileHeight,self.longitude-tileWidth)
  result << other.to_address.slice(0,zoom_level+1)


  other=Geo::Location.new(self.latitude,self.longitude+tileWidth)
  result << other.to_address.slice(0,zoom_level+1)

  other=Geo::Location.new(self.latitude,self.longitude-tileWidth)
  result << other.to_address.slice(0,zoom_level+1)


end

#to_address ⇒ Object 



16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
 
# File 'lib/sdb_dal/geo.rb', line 16

def to_address
	if latitude==nil || longitude==nil
		return nil
	end      
	address='t'
  right=0
  top=0
  width=180.0
  height=90.0
  16.times do

    if latitude>top
      top=top+height/2.0
      if longitude<right
        right=right-width/2.0
        address<<'q'
      else
        right=right+width/2.0
        address << 'r'
      end
    else

      top=top-height/2.0
      if longitude<right
        right=right-width/2.0
        address<<'t'
      else
        right=right+width/2.0
        address << 's'
      end
    end
    width=width/2.0
    height=height/2.0
#    puts "#{address} w=#{width}  h=#{height} r=#{right}  t=#{top}"
  end
  return address
end