学习曲线绘制

from sklearn.datasets import load_iris
from sklearn.neural_network import MLPClassifier
from sklearn.model_selection import train_test_split
from sklearn.preprocessing import StandardScaler
from sklearn.metrics import accuracy_score
iris = load_iris()
X, y = iris.data, iris.target
scaler = StandardScaler()
X = scaler.fit_transform(X)
for ratio in [0.3, 0.5, 0.7]:
    X_train, X_test, y_train, y_test = train_test_split(X, y, train_size=ratio, random_state=42)
    clf = MLPClassifier(hidden_layer_sizes=(10,), max_iter=500, random_state=42)
    clf.fit(X_train, y_train)
    print(f'{ratio}: 训练={accuracy_score(y_train, clf.predict(X_train)):.4f}, 测试={accuracy_score(y_test, clf.predict(X_test)):.4f}')