Module: Sass::Script::Functions::RandomSass

Included in:
Sass::Script::Functions
Defined in:
lib/random_sass.rb

Instance Method Summary collapse

Instance Method Details

#assert_same_unit(value1, value2, name = nil) ⇒ Object

A couple of handy assert for type validation.

Raises:

  • (ArgumentError) 


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# File 'lib/random_sass.rb', line 42

def assert_same_unit(value1, value2, name = nil)
  return if value1.unit_str == value2.unit_str
  err = "#{value1} has different units than #{value2}"
  err = "$#{name}: " + err if name
  raise ArgumentError.new(err)
end

#assert_unitless(value, name = nil) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/random_sass.rb', line 49

def assert_unitless(value, name = nil)
  assert_type value, :Number

  return if value.unitless?

  err = "#{value} is not unitless"
  err = "$#{name}: " + err if name
  raise ArgumentError.new(err)
end

#normal(p_mean, p_std) ⇒ Object

Returns a random number belonging to the set N(p_mean,p_std)



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# File 'lib/random_sass.rb', line 27

def normal(p_mean,p_std)
  assert_type p_mean, :Number
  assert_unitless p_std

  u = Random.rand(100000)/100000.0
  v = Random.rand(100000)/100000.0

  z = Math.sqrt(-2*Math.log(u)) * Math.cos(2*Math::PI*v)

  out_value = p_std.value * z + p_mean.value

  Sass::Script::Number.new(out_value,p_mean.numerator_units,p_mean.denominator_units)
end

#uniform(p_min, p_max) ⇒ Object

Returns a random number belonging to the set U(p_min,p_max)



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# File 'lib/random_sass.rb', line 12

def uniform(p_min,p_max)

  assert_type p_min, :Number
  assert_type p_max, :Number
  assert_same_unit p_max, p_min

  n_max = [p_max.value,p_min.value].max
  n_min = [p_max.value,p_min.value].min

  out_value = n_min + Random.rand(n_max-n_min)

  Sass::Script::Number.new(out_value,p_max.numerator_units,p_max.denominator_units)
end