Class: SPCore::TukeyWindow

Inherits:
Object
  • Object
show all
Defined in:
lib/spcore/windows/tukey_window.rb

Overview

For more info, see en.wikipedia.org/wiki/Window_function#Tukey_window.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(size, alpha = 0.5) ⇒ TukeyWindow

Returns a new instance of TukeyWindow.



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# File 'lib/spcore/windows/tukey_window.rb', line 9

def initialize size, alpha = 0.5
  @data = Array.new(size)
  
  left = (alpha * (size - 1) / 2.0).to_i
  right = ((size - 1) * (1.0 - (alpha / 2.0))).to_i
  
  size_min_1 = size - 1
  
  for n in 0...left
    x = Math::PI * (((2.0 * n) / (alpha * size_min_1)) - 1.0)
    @data[n] = 0.5 * (1.0 + Math::cos(x))
  end
  
  for n in left..right
    @data[n] = 1.0
  end
  
  for n in (right + 1)...size
    x = Math::PI * (((2 * n) / (alpha * size_min_1)) - (2.0 / alpha) + 1.0)
    @data[n] = 0.5 * (1.0 + Math::cos(x))
  end
end

Instance Attribute Details

#data ⇒ Object (readonly)

Returns the value of attribute data.



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# File 'lib/spcore/windows/tukey_window.rb', line 8

def data
  @data
end