def auto_simplify(ind, error_function, steps, printBool, progress_interval, maintain_ancestors = False):
'''
Auto-simplifies the provided individual.
'''
if printBool:
print '\nAuto-simplifying with starting size: ' + str(util.count_points(ind['program']))
looping = True
step = 0
program = ind['program']
errors = ind['errors']
total_errors = ind['total-error']
while looping:
if printBool and (step >= steps or step % progress_interval == 0):
print '\nstep: ' + step + '\nprogram: ' + str(program) + '\nerrors: ' + str(errors) + '\ntotal: ' + str(total_errors) + '\nsize: ' + str(util.count_points(program))
if step >= steps:
if maintain_ancestors:
ancestors = [ind['program']] + ind['ancestors']
else:
ancestors = ind['ancestors']
return individual.make_induvidual(program = program, errors = errors, total_errors = total_errors, history = ind['history'], ancestors = ancestors)
else:
if random_push.lrand_int(5)< 4:
p = program
how_many = random_push.lrand_int(2)+1
looping2 = True
while looping2:
if how_many == 0:
new_program = p
looping2 = False
else:
p = util.remove_code_at_point(p, random_push.lrand_int(util.count_points(p)))
how_many -= 1
point_index = random_push.lrand_int(util.count_points(program))
point = util.code_at_point(program, point_index)
if type(point) == list:
new_program = util.insert_code_at_point(program, point_index, flatten_seqs(point))
else:
new_program = program
new_errors = error_function(new_program)
new_total_errors = evaluate.compute_total_error(new_errors)
if new_errors == errors:
step += 1
program = new_program
errors = new_errors
total_errors = new_total_errors
else:
step += 1
def choose_node_index_by_tournament(tree, node_selection_tournament_size):
'''
Returns an index into tree, choosing the largest subtree found in
a tournament of size node-selection-tournament-size.
'''
c = util.count_points(tree)
tournament_set = []
for i in range(node_selection_tournament_size):
point_index = random_push.lrand_int(c)
subtree_size = util.count_points(util.code_at_point(tree, point_index))
tournament_set.append({'i' : point_index, 'size' : subtree_size})
biggest = tournament_set[0]
for s in tournament_set:
if biggest['size'] < s['size']:
biggest = s
return biggest['i']
def select_node_index(tree, keys):
'''
Returns an index into tree using the node selection method indicated
by node-selection-method.
'''
if keys['node-selection-method'] == 'unbiased':
return random_push.lrand_int(util.count_points(tree))
elif keys['node-selection-method'] == 'leaf-probability':
return choose_node_index_with_leaf_probability(tree, keys['node-selection-leaf-probability'])
elif keys['node-selection-method'] == 'size-tournament':
return choose_node_index_by_tournament(tree, keys['node-selection-tournament-size'])
else:
print 'ERROR: :node-selection-method set to unrecognized value '