Kahan summation: Difference between revisions

=={{header|Crystal}}==

{{works with|crystal|0.31.1}}

{{trans|C++}}

<lang crystal>def epsilon

eps = 1.0_f32

while 1.0_f32 + eps != 1.0_f32

eps /= 2.0_f32

end

eps

end

def kahan(nums)

sum = 0.0_f32

c = 0.0_f32

nums.each do |num|

y = num - c

t = sum + y

c = (t - sum) - y

sum = t

end

sum

end

a = 1.0_f32

b = epsilon

c = -b

puts "Epsilon = #{b}"

puts "Sum = #{a + b + c}"

puts "Kahan sum = #{kahan([a, b, c])}"</lang>

{{out}}

<pre>Epsilon = 5.9604645e-8

Sum = 0.99999994

Kahan sum = 1.0

</pre>