Class: EntropyTest

Inherits:
Test::Unit::TestCase
  • Object
show all
Includes:
MoreMath::Functions
Defined in:
tests/entropy_test.rb

Instance Method Summary collapse

Methods included from MoreMath::Functions

#beta, beta, #beta_regularized, beta_regularized, #cantor_pairing, cantor_pairing, #cantor_pairing_inv, cantor_pairing_inv, #erf, #erfc, #gamma, gamma, #gammaP_regularized, gammaP_regularized, #gammaQ_regularized, gammaQ_regularized, #log_beta, log_beta, #log_ceil, log_ceil, #log_floor, log_floor, #log_gamma, #logb, logb, #numberify_string, numberify_string, #stringify_number, stringify_number

Methods included from MoreMath::Entropy

#collision_entropy_per_symbol, #collision_entropy_total, #entropy_ideal, #entropy_maximum, #entropy_per_symbol, #entropy_probabilities, #entropy_ratio, #entropy_total, #minimum_entropy_per_symbol, #minimum_entropy_total

Methods included from MoreMath::Lambert

#lambert_w

Instance Method Details

#setup ⇒ Object

The setup method initializes instance variables with various string values.

This method prepares the object with predefined string constants for testing and demonstration purposes. It sets up empty strings, strings of specific lengths, and strings containing various character sets including ASCII, Unicode, and Japanese characters.



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# File 'tests/entropy_test.rb', line 15

def setup
  @empty  = ''
  @low    = ?A * 42
  @string = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit'
  @high   = 'The quick brown fox jumps over the lazy dog'
  @random = "\xAC-\x8A\xF5\xA8\xF7\\\e\xB5\x8CI\x06\xA7"
  @hi     = "こんにちは世界"
end

#test_collision_entropy_per_symbol ⇒ Object 



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# File 'tests/entropy_test.rb', line 93

def test_collision_entropy_per_symbol
  # For a uniform distribution, collision entropy = log2(size)
  assert_in_delta 2.0, collision_entropy_per_symbol('ABCD'), 1e-12

  # All symbols the same → 0
  assert_in_delta 0.0, collision_entropy_per_symbol('AAAA'), 1e-12

  # Empty string → 0
  assert_in_delta 0.0, collision_entropy_per_symbol(''), 1e-12
end

#test_collision_entropy_total ⇒ Object 



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# File 'tests/entropy_test.rb', line 120

def test_collision_entropy_total
  text = 'ABCD'
  per = collision_entropy_per_symbol(text)
  assert_in_delta per * text.size, collision_entropy_total(text), 1e-12

  assert_in_delta 0.0, collision_entropy_total(''), 1e-12
end

#test_entropy ⇒ Object 



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# File 'tests/entropy_test.rb', line 24

def test_entropy
  assert_in_delta 0.0, entropy(@empty), 1e-12
  assert_in_delta 0.0, entropy(@low),    1e-12
  assert_in_delta 3.951, entropy(@string), 1e-3
  assert_in_delta 4.431, entropy(@high),   1e-3
  assert_in_delta 3.700, entropy(@random), 1e-3
  assert_in_delta 2.807, entropy(@hi),     1e-3
end

#test_entropy_ideal ⇒ Object 



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# File 'tests/entropy_test.rb', line 33

def test_entropy_ideal
  assert_in_delta 0.0, entropy_ideal(-1), 1e-12
  assert_in_delta 0.0, entropy_ideal(0),  1e-12
  assert_in_delta 0.0, entropy_ideal(0.5), 1e-12
  assert_in_delta 0.0, entropy_ideal(1),  1e-12
  assert_in_delta 1.0,   entropy_ideal(2), 1e-3
  assert_in_delta 1.584, entropy_ideal(3), 1e-3
  assert_in_delta 3.0,   entropy_ideal(8), 1e-3
  assert_in_delta 3.321, entropy_ideal(10), 1e-3
  assert_in_delta 4.0,   entropy_ideal(16), 1e-3
end

#test_entropy_maximum ⇒ Object 



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# File 'tests/entropy_test.rb', line 45

def test_entropy_maximum
  text = 'A' * 64
  assert_equal 0, entropy_maximum(text, size: -1)
  assert_equal 0, entropy_maximum(text, size: 0)
  assert_equal 0, entropy_maximum(text, size: 1)
  assert_equal 64, entropy_maximum(text, size: 2)
  assert_equal 256, entropy_maximum(text, size: 16)
  assert_equal 128, entropy_maximum(text[0, 32], size: 16)
end

#test_entropy_probabilities ⇒ Object 



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# File 'tests/entropy_test.rb', line 65

def test_entropy_probabilities
  probs = entropy_probabilities('ABAB')
  assert_equal 0.5, probs['A']
  assert_equal 0.5, probs['B']

  probs = entropy_probabilities('AAAA')
  assert_equal 1.0, probs['A']

  probs = entropy_probabilities([])
  assert_equal({}, probs)

  # Ensure the method accepts an Array of symbols
  probs = entropy_probabilities(['x', 'y', 'x'])
  assert_equal 2.0 / 3.0, probs['x']
  assert_equal 1.0 / 3.0, probs['y']
end

#test_entropy_ratio ⇒ Object 



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# File 'tests/entropy_test.rb', line 55

def test_entropy_ratio
  assert_in_delta 0.0, entropy_ratio(@empty, size: 128), 1e-12
  assert_in_delta 0.0, entropy_ratio(@low, size: 128), 1e-12
  assert_in_delta 0.564, entropy_ratio(@string, size: 128), 1e-3
  assert_in_delta 0.633, entropy_ratio(@high, size: 128), 1e-3
  assert_in_delta 1.0,   entropy_ratio(@random, size: @random.size), 1e-3
  assert_in_delta 0.462, entropy_ratio(@random, size: 256), 1e-3
  assert_in_delta 0.253, entropy_ratio(@hi, size: 2_136), 1e-3
end

#test_entropy_total ⇒ Object 



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# File 'tests/entropy_test.rb', line 104

def test_entropy_total
  text = 'ABCD'
  per = entropy_per_symbol(text)
  assert_in_delta per * text.size, entropy_total(text), 1e-12

  assert_in_delta 0.0, entropy_total(''), 1e-12
end

#test_minimum_entropy_per_symbol ⇒ Object 



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# File 'tests/entropy_test.rb', line 82

def test_minimum_entropy_per_symbol
  # Uniform distribution → entropy equals log2(size)
  assert_in_delta 2.0, minimum_entropy_per_symbol('ABCD'), 1e-12

  # Single symbol → 0
  assert_in_delta 0.0, minimum_entropy_per_symbol('AAAA'), 1e-12

  # Empty string → 0
  assert_in_delta 0.0, minimum_entropy_per_symbol(''), 1e-12
end

#test_minimum_entropy_total ⇒ Object 



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# File 'tests/entropy_test.rb', line 112

def test_minimum_entropy_total
  text = 'ABCD'
  per = minimum_entropy_per_symbol(text)
  assert_in_delta per * text.size, minimum_entropy_total(text), 1e-12

  assert_in_delta 0.0, minimum_entropy_total(''), 1e-12
end