我正在尝试实现自己的kNN分类器。我已经实现了一些东西,但速度非常慢...
def euclidean_distance(X_train, X_test):
"""
Create list of all euclidean distances between the given
feature vector and all other feature vectors in the training set
"""
return [np.linalg.norm(X - X_test) for X in X_train]
def k_nearest(X, Y, k):
"""
Get the indices of the nearest feature vectors and return a
list of their classes
"""
idx = np.argpartition(X, k)
return np.take(Y, idx[:k])
def predict(X_test):
"""
For each feature vector get its predicted class
"""
distance_list = [euclidean_distance(X_train, X) for X in X_test]
return np.array([Counter(k_nearest(distances, Y_train, k)).most_common()[0][0] for distances in distance_list])
其中(例如)
X = [[ 1.96701284 6.05526865]
[ 1.43021202 9.17058291]]
Y = [ 1. 0.]
显然,如果我不使用任何for循环,速度会更快,但是我不知道如何在没有它们的情况下使其工作。有没有一种方法可以在不使用for循环/列表推导的情况下完成这个任务?
X_train
是什么? - DivakarX
分成了训练集和测试集。假设X
实际上是200行的x, y
值,而不仅仅是2个。然后将其分成X_train
和X_test
。 - user5368737