Сюжет Python scikit-fuzzy не отвечает

Здравствуйте, я попытался создать нечеткую систему с помощью scikit-fuzzy, вывод работает хорошо, но когда я пытаюсь понять его в соответствии с новым API scikit-fuzzy, мой график не отвечает. Я помню, когда в прошлый раз, когда я использовал scikit-fuzzy, мой график работал хорошо, что не так? В моем коде чего-то не хватает?

import numpy as np
import skfuzzy as fuzz
from skfuzzy import control as ctrl

# crisp set
keramaian = ctrl.Antecedent(np.arange(0, 30, 1), 'KERAMAIAN')
ukuran = ctrl.Antecedent(np.arange(0, 25, 1), 'UKURAN')
vol = ctrl.Consequent(np.arange(0, 100, 1), 'UKURAN VOLUME')

# fuzzyfication
ukuran['Kecil'] = fuzz.trimf(ukuran.universe, [0, 0, 13])
ukuran['Sedang'] = fuzz.trimf(ukuran.universe, [0, 12, 24])
ukuran['Besar'] = fuzz.trimf(ukuran.universe, [12, 24, 24])

keramaian['sunyi'] = fuzz.trimf(keramaian.universe, [0, 0, 15])
keramaian['Cukup Ramai'] = fuzz.trimf(keramaian.universe, [0, 15, 29])
keramaian['Berisik'] = fuzz.trimf(keramaian.universe, [15, 29, 29])

vol['Pelan'] = fuzz.trimf(vol.universe, [0, 0, 40])
vol['Sedang'] = fuzz.trimf(vol.universe, [30, 50, 70])
vol['Kencang'] = fuzz.trimf(vol.universe, [60, 99, 99])

# rule set
rule1 = ctrl.Rule(ukuran['Kecil'] & keramaian['Berisik'], vol['Kencang'])
rule2 = ctrl.Rule(ukuran['Kecil'] & keramaian['Cukup Ramai'], vol['Kencang'])
rule3 = ctrl.Rule(ukuran['Kecil'] & keramaian['Cukup Ramai'], vol['Kencang'])
rule4 = ctrl.Rule(ukuran['Sedang'] & keramaian['Berisik'], vol['Sedang'])
rule5 = ctrl.Rule(ukuran['Sedang'] & keramaian['Cukup Ramai'], vol['Sedang'])
rule6 = ctrl.Rule(ukuran['Sedang'] & keramaian['sunyi'], vol['Sedang'])
rule7 = ctrl.Rule(ukuran['Besar'] & keramaian['Berisik'], vol['Pelan'])
rule8 = ctrl.Rule(ukuran['Besar'] & keramaian['Cukup Ramai'], vol['Pelan'])
rule9 = ctrl.Rule(ukuran['Besar'] & keramaian['sunyi'], vol['Pelan'])

vol_suara_ctrl = ctrl.ControlSystem([rule1, rule2, rule3, rule4, rule5, rule6, rule7, rule8, rule9])
vol_suara = ctrl.ControlSystemSimulation(vol_suara_ctrl)
keramaian['sunyi'].view()
vol_suara.input['KERAMAIAN'] = int(input("Masukkan jumlah keramaian?\n"))
vol_suara.input['UKURAN'] = int(input("Masukkan ukuran speaker?\n"))

# defuzification
vol_suara.compute()
vol.view(sim=vol_suara)

print(vol_suara.output['UKURAN VOLUME'])