ruby - Query Mongoid for all circle areas that include a given point -

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let have 2 classes:

class cirle   include mongoid::document    field :lat, type: float   field :lon, type: float   field :radius, type: integer  end   class point   include mongoid::document    field :lat, type: float   field :lon, type: float end

how can find circles include given point?

i'm not familiar mongoid, perhaps following help. suppose:

circles = [   { x: 1, y: 2, radius: 3 },   { x: 3, y: 1, radius: 2 },   { x: 2, y: 2, radius: 4 }, ]

and

point = { x: 4.5, y: 1 }

then circles containing point obtained of math::hypot:

circles.select { |c|   math.hypot((c[:x]-point[:x]).abs, (c[:y]-point[:y]).abs) <= c[:radius] }   #=> [{ x: 3, y: 1, radius: 2 }, { x: 2, y: 2, radius: 4 }]

edit: improve efficiency @drenmi suggests:

x, y = point.values_at(:x, :y) circles.select |c|   d0, d1, r = (c[:x]-x).abs, (c[:y]-y).abs, c[:radius]   d0*d0 + d1*d1 <= r*r end

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