scikit-learn的RandomizedPCA模块不起作用

Question

In [4]: from sklearn import decomposition

In [5]: decomposition.PCA
Out[5]: sklearn.decomposition.pca.PCA

In [6]: decomposition.RandomizedPCA
Traceback (most recent call last):

  File "<ipython-input-6-aace1bd9eb39>", line 1, in <module>
    decomposition.RandomizedPCA

AttributeError: module 'sklearn.decomposition' has no attribute 'RandomizedPCA'

为什么有PCA但没有随机PCA？它是否已从scikit-learn中删除？我很困惑。