我想使用单词以及一些附加功能(例如,具有链接)在文本上构建分类模型
tweets = ['this tweet has a link htt://link','this one does not','this one does http://link.net']
我使用 sklearn 来获取文本数据的稀疏矩阵
tfidf_vectorizer = TfidfVectorizer(max_df=0.90, max_features=200000,
min_df=0.1, stop_words='english',
use_idf=True, ntlk.tokenize,ngram_range=(1,2))
tfidf_matrix = tfidf_vectorizer.fit_transform(tweets)
我想向其添加列以支持文本数据的其他功能。我试过:
import scipy as sc
all_data = sc.hstack((tfidf_matrix, [1,0,1]))
这给了我如下所示的数据:
array([ <3x8 sparse matrix of type '<type 'numpy.float64'>'
with 10 stored elements in Compressed Sparse Row format>,
1, 1, 0], dtype=object)
当我将此数据框馈送到模型时:
`from sklearn.naive_bayes import MultinomialNB
clf = MultinomialNB().fit(all_data, y)`
我收到回溯错误:
`Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:Anacondalibsite- packagesspyderlibwidgetsexternalshellsitecustomize.py", line 580, in runfile
execfile(filename, namespace)
File "C:/Users/c/Desktop/features.py", line 157, in <module>
clf = MultinomialNB().fit(all_data, y)
File "C:Anacondalibsite-packagessklearnnaive_bayes.py", line 302, in fit
_, n_features = X.shape
值错误:需要 1 个以上的值才能解压缩"
编辑:数据的形状
`tfidf_matrix.shape
(100, 2)
all_data.shape
(100L,)`
是否可以将列直接附加到稀疏矩阵?如果没有,我应该如何将数据转换为可以支持此功能的格式?我担心稀疏矩阵以外的内容会增加内存占用。
"我可以将列直接附加到稀疏矩阵吗?" - 是的。您可能应该这样做,因为解包(使用todense
或toarray
)很容易导致大型语料库中的内存爆炸。
使用 scipy.sparse.hstack:
import numpy as np
import scipy as sp
from sklearn.feature_extraction.text import TfidfVectorizer
tweets = ['this tweet has a link htt://link','this one does not','this one does http://link.net']
tfidf_vectorizer = TfidfVectorizer()
tfidf_matrix = tfidf_vectorizer.fit_transform(tweets)
print tfidf_matrix.shape
(3, 10)
new_column = np.array([[1],[0],[1]])
print new_column.shape
(3, 1)
final = sp.sparse.hstack((tfidf_matrix, new_column))
print final.shape
(3, 11)
将稀疏矩阵转换为密集矩阵
import numpy as np
from sklearn.feature_extraction.text import TfidfVectorizer
tweets = ['this tweet has a link htt://link','this one does not','this one does http://link.net']
tfidf_vectorizer = TfidfVectorizer()
tfidf_matrix = tfidf_vectorizer.fit_transform(tweets)
dense = tfidf_matrix.todense()
print dense.shape
newCol = [[1],[0],[1]]
allData = np.append(dense, newCol, 1)
print allData.shape
(3升、10升)
(3升、11升)
这是正确的形式:
all_data = sc.hstack([tfidf_matrix, sc.csr_matrix([1,0,1]).T], 'csr')