Question

我的文字显示如下：

 list1 = ["My name is xyz", "My name is pqr", "I work in abc"]

以上将是使用kmeans对文本进行聚类的训练集。

list2 = ["My name is xyz", "I work in abc"]

以上是我的测试集。

我已经构建了一个矢量化器和模型，如下所示：

vectorizer = TfidfVectorizer(min_df = 0, max_df=0.5, stop_words = "english", charset_error = "ignore", ngram_range = (1,3))
vectorized = vectorizer.fit_transform(list1)
km=KMeans(n_clusters=2, init='k-means++', n_init=10, max_iter=1000, tol=0.0001, precompute_distances=True, verbose=0, random_state=None, copy_x=True, n_jobs=1)
km.fit(vectorized)

如果我尝试为我的测试集“list2”预测集群：

km.predict(list2)

我收到以下错误：

ValueError: Incorrect number of features. Got 2 features, expected 5

有人告诉我使用Pipeline来解决这个问题。所以我写了下面的代码：

pipe = Pipeline([('vect', vectorizer), ('vectorized', vectorized), ('kmeans',km )])

但我收到错误：

TypeError                                 Traceback (most recent call last)
/mnt/folder/Text_Mining/<ipython-input-14-321cabc3bf35> in <module>()
----> 1 pipe = Pipeline([('vect', vectorizer), ('vectorized', vectorized), ('kmeans',km )])
/usr/local/lib/python2.7/dist-packages/scikit_learn-0.13-py2.7-linux-x86_64.egg/sklearn/pipeline.pyc in __init__(self, steps)
     87                 raise TypeError("All intermediate steps a the chain should "
     88                                 "be transforms and implement fit and transform"
---> 89                                 "'%s' (type %s) doesn't)" % (t, type(t)))
     90
     91         if not hasattr(estimator, "fit"):
TypeError: All intermediate steps a the chain should be transforms and implement fit and transform'  (0, 2)     1.0
(1, 4)        0.57735026919
(1, 3)        0.57735026919
(1, 1)        0.57735026919
(2, 0)        1.0' (type <class 'scipy.sparse.csr.csr_matrix'>) doesn't)

我认为vectorized的输出可能没有实现拟合和变换，但在这种特殊情况下我该怎么做呢？我是机器学习的新手。另外，如何从kmeans模型中获取标签？当我运行kmeans时，我可以使用km.labels_访问群集标签。如何在Pipeline中做类似的事情？

Answer 1

您需要做的是使用vectorizer训练list1，然后使用相同的矢量化合物，transform list1和{{ 1}}。这将解决问题。演示：

list2

Answer 2

您非常亲密！跳过中间的显式vectorizer.fit()步骤，并在管道中完成所有步骤：

list1 = ["My name is xyz", "My name is pqr", "I work in abc"]
list2 = ["My name is xyz", "I work in abc"]
vectorizer = TfidfVectorizer(min_df = 0, max_df=0.5, stop_words = "english", ngram_range = (1,3))
km = KMeans(n_clusters=2, init='k-means++', n_init=10, max_iter=1000, tol=0.0001, precompute_distances=True, verbose=0, random_state=None, copy_x=True, n_jobs=1)
pipe = Pipeline([('vect', vectorizer), ('kmeans', km)])
pipe.fit(list1)
pipe.transform(list2)

结果：

array（[[0.70710678，1.41421356]， [0.70710678，1.41421356]]

注意：调整了几个参数，使其可以在我当前的sklearn（0.22.1）版本上运行...已经有几年了：-）

Sklearn Pipeline：如何构建k表示，聚类文本？

2 个答案: