Method: EvoSynth::Problems::FloatBenchmarkFuntions.griewank

Defined in:
lib/evosynth/problems/float_benchmark_functions.rb

.griewank(xs) ⇒ Object

Griewank (Törn & Zilinskas 1989)

global minimum: f(x) = 0 at x(i) = 0, i = 1..n



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# File 'lib/evosynth/problems/float_benchmark_functions.rb', line 91

def FloatBenchmarkFuntions.griewank(xs)
  product = 1.0
  xs.each_with_index { |x, i| product *= Math.cos x / Math.sqrt(i+1) }
  1 + xs.inject(0.0) { |sum, x| sum += x**2 / (400 * xs.size) } - product
end