Class: Philiprehberger::Approx::Comparator

Inherits:
Object
  • Object
show all
Defined in:
lib/philiprehberger/approx/comparator.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(epsilon: 1e-9, relative: nil) ⇒ Comparator

Create a reusable comparator with preset tolerances

Parameters:

  • epsilon (Float, nil) (defaults to: 1e-9) —

    absolute tolerance

  • relative (Float, nil) (defaults to: nil) —

    relative tolerance



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# File 'lib/philiprehberger/approx/comparator.rb', line 12

def initialize(epsilon: 1e-9, relative: nil)
  @epsilon = epsilon
  @relative = relative
end

Instance Attribute Details

#epsilon ⇒ Object (readonly)

Returns the value of attribute epsilon.



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# File 'lib/philiprehberger/approx/comparator.rb', line 6

def epsilon
  @epsilon
end

#relative ⇒ Object (readonly)

Returns the value of attribute relative.



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# File 'lib/philiprehberger/approx/comparator.rb', line 6

def relative
  @relative
end

Instance Method Details

#assert_near(a, b) ⇒ Object

Assert that two values are approximately equal, raising on mismatch

Parameters:

  • a (Numeric, Array, Hash) —

    first value

  • b (Numeric, Array, Hash) —

    second value

Raises:

  • (Error) —

    if values are not approximately equal



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# File 'lib/philiprehberger/approx/comparator.rb', line 55

def assert_near(a, b)
  return if equal?(a, b)

  raise Error, "expected #{a.inspect} to be near #{b.inspect} (epsilon: #{@epsilon}, relative: #{@relative})"
end

#assert_within(a, b) ⇒ Object

Assert that two values pass within?, raising on mismatch

Parameters:

  • a (Numeric, Array, Hash) —

    first value

  • b (Numeric, Array, Hash) —

    second value

Raises:

  • (Error) —

    if values fail both tolerance checks



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# File 'lib/philiprehberger/approx/comparator.rb', line 102

def assert_within(a, b)
  Approx.assert_within(a, b, abs: @epsilon, rel: @relative)
end

#between?(value, min, max) ⇒ Boolean

Check if a numeric value lies within [min, max] with epsilon slack

Parameters:

  • value (Numeric) —

    value to test

  • min (Numeric) —

    inclusive lower bound

  • max (Numeric) —

    inclusive upper bound

Returns:

  • (Boolean) 


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# File 'lib/philiprehberger/approx/comparator.rb', line 93

def between?(value, min, max)
  Approx.between?(value, min, max, epsilon: @epsilon)
end

#clamp(value, target) ⇒ Numeric

Snap a value to target if approximately equal, otherwise return unchanged

Parameters:

  • value (Numeric) —

    the value to potentially snap

  • target (Numeric) —

    the target to snap to

Returns:

  • (Numeric) —

    target if approximately equal, otherwise value



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# File 'lib/philiprehberger/approx/comparator.rb', line 75

def clamp(value, target)
  Approx.clamp(value, target, epsilon: @epsilon)
end

#equal?(a, b) ⇒ Boolean

Check if two values are approximately equal using configured tolerances

Parameters:

  • a (Numeric, Array, Hash) —

    first value

  • b (Numeric, Array, Hash) —

    second value

Returns:

  • (Boolean) 


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# File 'lib/philiprehberger/approx/comparator.rb', line 22

def equal?(a, b)
  if @relative && @epsilon
    Approx.within?(a, b, abs: @epsilon, rel: @relative)
  elsif @relative
    Approx.relative_equal?(a, b, tolerance: @relative)
  else
    Approx.equal?(a, b, epsilon: @epsilon)
  end
end

#near?(a, b) ⇒ Boolean

Alias for #equal? matching the module-level near? naming

Parameters:

  • a (Numeric, Array, Hash) —

    first value

  • b (Numeric, Array, Hash) —

    second value

Returns:

  • (Boolean) 


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# File 'lib/philiprehberger/approx/comparator.rb', line 37

def near?(a, b)
  equal?(a, b)
end

#relative_equal?(a, b) ⇒ Boolean

Check if two values are approximately equal using relative tolerance

Parameters:

  • a (Numeric, Array, Hash) —

    first value

  • b (Numeric, Array, Hash) —

    second value

Returns:

  • (Boolean) 


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# File 'lib/philiprehberger/approx/comparator.rb', line 66

def relative_equal?(a, b)
  Approx.relative_equal?(a, b, tolerance: @relative || @epsilon)
end

#within?(a, b) ⇒ Boolean

Check using combined absolute + relative tolerance from the configured comparator

Parameters:

  • a (Numeric, Array, Hash) —

    first value

  • b (Numeric, Array, Hash) —

    second value

Returns:

  • (Boolean) 


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# File 'lib/philiprehberger/approx/comparator.rb', line 46

def within?(a, b)
  Approx.within?(a, b, abs: @epsilon, rel: @relative)
end

#zero?(value) ⇒ Boolean

Check if a numeric value is approximately zero

Parameters:

  • value (Numeric) —

    value to test

Returns:

  • (Boolean) 


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# File 'lib/philiprehberger/approx/comparator.rb', line 83

def zero?(value)
  Approx.zero?(value, epsilon: @epsilon)
end