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@fujimura
Created March 2, 2018 11:30
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require 'json'
def get_lonlat_in_spiral(i)
v = Complex.polar i, i/4.9 * Math::PI/2
angle = v.angle
magnitude = v.magnitude
[magnitude * Math.cos(angle), magnitude * Math.sin(angle)]
end
r = 10.upto(30).map { |i| get_lonlat_in_spiral(i) }
coords = r.map {|x, y| [139.6 + y * 0.01, 35.7 + x * 0.01] }
puts JSON.generate(
type: "MultiPolygon",
coordinates: [coords.map {|y, x| [y.floor(5), x.floor(5)] }.map { |y, x|
[
[y, x],
[y, x + 0.01],
[y - 0.01, x + 0.01],
[y - 0.01, x],
[y, x]
]
}]
)
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