Class: Tonal::Step

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
Comparable
Defined in:
lib/tonal/step.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(modulo: nil, log: nil, step: nil, ratio: nil) ⇒ Step

Returns a new instance of Step.

Raises:

  • (ArgumentError) 


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# File 'lib/tonal/step.rb', line 9

def initialize(modulo: nil, log: nil, step: nil, ratio: nil)
  raise ArgumentError, "modulo: required" unless modulo
  raise ArgumentError, "One of log:, step: or ratio: must be provided" unless [log, step, ratio].compact.count == 1
  @modulo = modulo.round

  if ratio
    @ratio, @log = derive_ratio_and_log(ratio: ratio)
  elsif step
    @ratio, @log = derive_ratio_and_log(step: step)
  elsif log
    @ratio, @log = derive_ratio_and_log(log: log)
  end

  @step = (modulo * @log).round
  @tempered = 2**(@step.to_f/@modulo)
end

Instance Attribute Details

#log ⇒ Object (readonly)

Returns the value of attribute log.



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# File 'lib/tonal/step.rb', line 7

def log
  @log
end

#modulo ⇒ Object (readonly)

Returns the value of attribute modulo.



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# File 'lib/tonal/step.rb', line 7

def modulo
  @modulo
end

#ratio ⇒ Object (readonly)

Returns the value of attribute ratio.



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# File 'lib/tonal/step.rb', line 7

def ratio
  @ratio
end

#step ⇒ Object (readonly)

Returns the value of attribute step.



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# File 'lib/tonal/step.rb', line 7

def step
  @step
end

#tempered ⇒ Object (readonly)

Returns the value of attribute tempered.



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# File 'lib/tonal/step.rb', line 7

def tempered
  @tempered
end

Instance Method Details

#+(rhs) ⇒ Object Also known as: % 



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# File 'lib/tonal/step.rb', line 87

def +(rhs)
  self.class.new(step: (rhs % modulo), modulo: modulo)
end

#<=>(rhs) ⇒ Object 



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# File 'lib/tonal/step.rb', line 92

def <=>(rhs)
  rhs.kind_of?(self.class) && modulo <=> rhs.modulo && log <=> rhs.log && step <=> rhs.step
end

#convert(new_modulo) ⇒ Tonal::Step

Returns new step with the ratio mapped to the new modulo.

Examples:

Tonal::Step.new(ratio: 3/2r, modulo: 31).convert(12)
=> 7\12

Returns:

  • (Tonal::Step) —

    new step with the ratio mapped to the new modulo



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# File 'lib/tonal/step.rb', line 36

def convert(new_modulo)
  self.class.new(log: log, modulo: new_modulo)
end

#efficiency ⇒ Tonal::Cents

Returns the difference between the step and the ratio.

Examples:

Tonal::Step.new(ratio: 3/2r, modulo: 31).efficiency
=> 5.19

Returns:

  • (Tonal::Cents) —

    the difference between the step and the ratio



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# File 'lib/tonal/step.rb', line 83

def efficiency
  ratio_to_cents - step_to_cents
end

#inspect ⇒ Object Also known as: to_s 



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# File 'lib/tonal/step.rb', line 26

def inspect
  "#{step}\\#{modulo}"
end

#ratio_to_cents ⇒ Tonal::Cents

Returns measure of ratio in cents.

Examples:

Tonal::Step.new(ratio: 3/2r, modulo: 31).ratio_to_cents
=> 701.96

Returns:



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# File 'lib/tonal/step.rb', line 74

def ratio_to_cents
  ratio.to_cents
end

#ratio_to_r ⇒ Rational

Returns of the ratio.

Examples:

Tonal::Step.new(ratio: 3/2r, modulo: 31).ratio_to_r
=> 3/2

Returns:

  • (Rational) —

    of the ratio



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# File 'lib/tonal/step.rb', line 55

def ratio_to_r
  ratio.to_r
end

#step_to_cents ⇒ Tonal::Cents Also known as: to_cents

Returns measure of step in cents.

Examples:

Tonal::Step.new(ratio: 3/2r, modulo: 31).step_to_cents
=> 696.77

Returns:



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# File 'lib/tonal/step.rb', line 64

def step_to_cents
  tempered.to_cents
end

#step_to_r ⇒ Rational Also known as: to_r

Returns of the step.

Examples:

Tonal::Step.new(ratio: 3/2r, modulo: 31).step_to_r
=> 6735213777669305/4503599627370496

Returns:

  • (Rational) —

    of the step



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# File 'lib/tonal/step.rb', line 45

def step_to_r
  tempered.to_r
end