RosettaCodeData/Task/Evolutionary-algorithm/Euphoria/evolutionary-algorithm.euph...

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constant table = "ABCDEFGHIJKLMNOPQRSTUVWXYZ "
function random_generation(integer len)
sequence s
s = rand(repeat(length(table),len))
for i = 1 to len do
s[i] = table[s[i]]
end for
return s
end function
function mutate(sequence s, integer n)
for i = 1 to length(s) do
if rand(n) = 1 then
s[i] = table[rand(length(table))]
end if
end for
return s
end function
function fitness(sequence probe, sequence target)
atom sum
sum = 0
for i = 1 to length(target) do
sum += power(find(target[i], table) - find(probe[i], table), 2)
end for
return sqrt(sum/length(target))
end function
constant target = "METHINKS IT IS LIKE A WEASEL", C = 30, MUTATE = 15
sequence parent, specimen
integer iter, best
atom fit, best_fit
parent = random_generation(length(target))
iter = 0
while not equal(parent,target) do
best_fit = fitness(parent, target)
printf(1,"Iteration: %3d, \"%s\", deviation %g\n", {iter, parent, best_fit})
specimen = repeat(parent,C+1)
best = C+1
for i = 1 to C do
specimen[i] = mutate(specimen[i], MUTATE)
fit = fitness(specimen[i], target)
if fit < best_fit then
best_fit = fit
best = i
end if
end for
parent = specimen[best]
iter += 1
end while
printf(1,"Finally, \"%s\"\n",{parent})