cross_val_score() di sklearn
Validasi Model di Python
Kasey Jones
Data Scientist
cross_val_score()
from sklearn.model_selection import cross_val_score
from sklearn.ensemble import RandomForestClassifier
rfc = RandomForestClassifier()
estimator: model yang digunakan
X: data prediktor
y: array respons
cv: jumlah lipatan cross-validation
cross_val_score(estimator=rfc, X=X, y=y, cv=5)
Menggunakan scoring dan make_scorer
Parameter scoring pada cross_val_score:
# Muat metodenya
from sklearn.metrics import mean_absolute_error, make_scorer
# Buat scorer
mae_scorer = make_scorer(mean_absolute_error)
# Gunakan scorer
cross_val_score(<estimator>, <X>, <y>, cv=5, scoring=mae_scorer)
Muat semua metode sklearn
from sklearn.ensemble import RandomForestRegressor
from sklearn.model_selection import cross_val_score
from sklearn.metrics import mean_squared_error, make_scorer
Buat model dan scorer
rfc = RandomForestRegressor(n_estimators=20, max_depth=5, random_state=1111)
mse = make_scorer(mean_squared_error)
Jalankan cross_val_score()
cv_results = cross_val_score(rfc, X, y, cv=5, scoring=mse)
Mengakses hasil
print(cv_results)
[196.765, 108.563, 85.963, 222.594, 140.942]
Laporan rata-rata dan standar deviasi:
print('The mean: {}'.format(cv_results.mean()))
print('The std: {}'.format(cv_results.std()))
The mean: 150.965
The std: 51.676
Ayo berlatih!
Validasi Model di Python
