Class: Scratchpad::Interpolator

Inherits:
Object
  • Object
show all
Includes:
Math
Defined in:
lib/scratchpad/interpolator.rb

Defined Under Namespace

Classes: DataPoint

Constant Summary collapse

X = 
0
Y = 
1

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Interpolator

Returns a new instance of Interpolator.



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# File 'lib/scratchpad/interpolator.rb', line 9

def initialize
  @x_v = nil
  @y_v = nil
  @x          = nil
  @y          = nil
  @ring = [nil, nil, nil]
end

Instance Method Details

#feed(x, y, is_down) ⇒ Object

(x, y) -> [[Float, Float, Float]]



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# File 'lib/scratchpad/interpolator.rb', line 21

def feed(x, y, is_down)
  raise unless @ring.size == 3

  @ring.shift
  @ring << [DataPoint.new(nil, x), DataPoint.new(nil, y), is_down]

  if @ring[1] == nil
    # cannot calculate yet
    return []
  else
    # calculate @ring[1]'s velocity
    if @ring[0] == nil
      @ring[1][X].v = (@ring[2][X].pos - @ring[1][X].pos)
      @ring[1][Y].v = (@ring[2][Y].pos - @ring[1][Y].pos)
      return []
    else
      @ring[1][X].v = ((@ring[1][X].pos - @ring[0][X].pos) + (@ring[2][X].pos - @ring[1][X].pos)) * 0.5
      @ring[1][Y].v = ((@ring[1][Y].pos - @ring[0][Y].pos) + (@ring[2][Y].pos - @ring[1][Y].pos)) * 0.5
      # unless @ring[1][2] # is_down
      #   return []
      # else
        return interpolate
#        end
    end
  end
end

#find_accelerations(s, velocity, target_position, target_velocity) ⇒ Object 



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# File 'lib/scratchpad/interpolator.rb', line 89

def find_accelerations(s, velocity, target_position, target_velocity)
  a = 0.0
  b = 0.0

  s_ = s
  velocity_ = velocity

  loop do
    s = s_
    velocity = velocity_

    (0..9).map { |n| n*0.1 }.map do |t|
      [t, s].tap do
        s += 0.1 * velocity
        if t < 0.5
          velocity += a * 0.1
        else
          velocity += b * 0.1
        end
      end
    end

    if (s - target_position).abs >= 0.001
      a += -(s - target_position) * 1.0
    elsif (velocity - target_velocity).abs >= 0.001
      b += -(velocity - target_velocity) * 1.0
    else
      return a, b
    end
  end
end

#interpolate ⇒ Object

interpolate using @ring and @ring



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# File 'lib/scratchpad/interpolator.rb', line 49

def interpolate
  a, b = find_accelerations(@ring[0][X].pos,
                              @ring[0][X].v,
                              @ring[1][X].pos,
                              @ring[1][X].v)
  s = @ring[0][X].pos
  velocity = @ring[0][X].v
  xpoints = (0..10).map { |n| n*0.1 }.map do |t|
    [s, velocity].tap do
      s += 0.1 * velocity 
      if t < 0.5
        velocity += a * 0.1
      else
        velocity += b * 0.1
      end
    end
  end

  a, b = find_accelerations(@ring[0][Y].pos,
                              @ring[0][Y].v,
                              @ring[1][Y].pos,
                              @ring[1][Y].v)
  s = @ring[0][Y].pos
  velocity = @ring[0][Y].v
  ypoints = (0..10).map { |n| n*0.1 }.map do |t|
    [s, velocity].tap do
      s += 0.1 * velocity 
      if t < 0.5
        velocity += a * 0.1
      else
        velocity += b * 0.1
      end
    end
  end

  return xpoints.zip(ypoints).map { |x_data, y_data|
    [x_data[0], y_data[0], sqrt(x_data[1] ** 2 + y_data[1] ** 2)]
  }
end