如何使用 sklearn KNN 預測值

Question

我無法使用 sklearn KNN model 進行預測。

import numpy as np
import sklearn.datasets
from sklearn.model_selection import train_test_split
from sklearn.neighbors import KNeighborsClassifier

data = sklearn.datasets.load_digits()
X_train, X_test, y_train, y_test = train_test_split(data['data'], data['target'])
model = KNeighborsClassifier().fit(X_train, y_train)
print(model.predict(X_test[0]))

它返回一個錯誤

Reshape your data either using array.reshape(-1, 1) if your data has a single feature or array.reshape(1, -1) if it contains a single sample.

當我重塑它時

print(model.predict(X_test[0].reshape(-1, 1))

它仍然返回一個錯誤

ValueError: query data dimension must match training data dimension

Answer 1

您想要預測第一個測試行，因此您應該改造成(1, -1) （錯誤消息中的“它包含一個樣本”）。