def evolve(pop, data, controls, generation=1):
"""This function examines each generation of programs, and if none meet
the termination criterion, evolves a new generation and calls itself
until an individual is found which satisfies the termination criterion,
at which point it returns a dictionary containing the solution program and
other info.
"""
print("Generation:", generation)
best_in_gen = pygp.termination_test(pop, data)
if best_in_gen[1] < controls["target_fitness"]:
return {"best":best_in_gen[0], "score":best_in_gen[1],
"gen": generation}
next_gen = []
for i in range(len(pop)):
choice = random()
if choice < controls["cross_rate"]:
child = pygp.subtree_crossover(pop, controls["tourn_size"], data)
elif choice < controls["rep_rate"]:
child = pygp.reproduction(pop, controls["tourn_size"], data)
elif choice < controls["mut_rate"]:
child = pygp.subtree_mutation(pop[i], controls["max_depth"])
next_gen.append(child)
return evolve(next_gen, data, controls, generation+1)
def evolve(pop, generation=1):
"""This function examines each generation of programs, and if none meet
the termination criterion, evolves a new generation and calls itself
until an individual is found which satisfies the termination criterion,
at which point it returns a dictionary with the solution program and
other info. This function can also be found in the majorelements module, but
is shown here for illustration.
"""
print(generation)
best_in_gen = pygp.termination_test(pop, data) # include a program return
if best_in_gen[1] < target_fitness:
return {"best":best_in_gen[0], "score":best_in_gen[1],
"gen": generation}
# if above fitness test fails, produce a new generation
next_gen = []
for i in range(len(pop)):
choice = random()
if choice < cross_rate:
child = pygp.subtree_crossover(pop, tourn_size, data)
elif choice < rep_rate:
child = pygp.reproduction(pop, tourn_size, data)
elif choice < mut_rate:
child = pygp.subtree_mutation(pop[i], max_depth)
next_gen.append(child)
# After producing a new generation, call recursively
return evolve(next_gen, generation+1)
