Module: Nuggets::Array::BoostMixin

Included in:
Array
Defined in:
lib/nuggets/array/boost_mixin.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.included(base) ⇒ Object 



33
34
35
 
# File 'lib/nuggets/array/boost_mixin.rb', line 33

def self.included(base)
  base.send :include, Nuggets::Array::MeanMixin
end

Instance Method Details

#boost(factor) ⇒ Object

call-seq:

array.boost(factor) => anArray

Maps each value in array to its “boosted” value according to factor. (Cf. #boost_factor)

Example:

a.boost(a.boost_factor(b)).mean == b.mean



71
72
73
 
# File 'lib/nuggets/array/boost_mixin.rb', line 71

def boost(factor)
  map { |x| x * (1 + factor) }
end

#boost_factor(other, &block) ⇒ Object Also known as: boof

call-seq:

array.boost_factor(other_array) => aFloat
array.boost_factor(other_array) { |array| ... } => aFloat

Calculates the “boost factor” from the series of values in array to the series of values in other_array by means of their arithmetic mean or the value returned from the block given.

Example:

# series of runtime measurements for old version
a = [1.5, 1.6, 1.4]

# series of runtime measurements for new version
b = [0.7, 0.8, 0.8]

# what speedup did we get? => almost 50%
a.boost_factor(b)  #=> -0.48888888888888893



55
56
57
58
 
# File 'lib/nuggets/array/boost_mixin.rb', line 55

def boost_factor(other, &block)
  block ||= :mean.to_proc
  block[other] / block[self] - 1
end