python doc2vec
时间: 2023-06-21 13:15:04 浏览: 57
Python Doc2Vec is an algorithm for generating vector representations of documents. It is an extension of the Word2Vec algorithm, which generates vector representations of words. Doc2Vec is used for tasks such as text classification, document similarity, and clustering.
The basic idea behind Doc2Vec is to train a neural network to predict the probability distribution of words in a document. The network takes both the document and a context word as input, and predicts the probability of each word in the vocabulary being the next word in the document. The output of the network is a vector representation of the document.
Doc2Vec can be implemented using the Gensim library in Python. The Gensim implementation of Doc2Vec has two modes: Distributed Memory (DM) and Distributed Bag of Words (DBOW). In DM mode, the algorithm tries to predict the next word in the document using both the context words and the document vector. In DBOW mode, the algorithm only uses the document vector to predict the next word.
To use Doc2Vec with Gensim, you need to first create a corpus of documents. Each document should be represented as a list of words. You can then create a Doc2Vec model and train it on the corpus. Once the model is trained, you can use it to generate vector representations of new documents.
Here's an example of training a Doc2Vec model using Gensim:
```
from gensim.models.doc2vec import Doc2Vec, TaggedDocument
from nltk.tokenize import word_tokenize
# create a corpus of documents
doc1 = TaggedDocument(words=word_tokenize("This is the first document."), tags=["doc1"])
doc2 = TaggedDocument(words=word_tokenize("This is the second document."), tags=["doc2"])
doc3 = TaggedDocument(words=word_tokenize("This is the third document."), tags=["doc3"])
corpus = [doc1, doc2, doc3]
# create a Doc2Vec model and train it on the corpus
model = Doc2Vec(corpus, vector_size=100, window=5, min_count=1, workers=4, epochs=50)
# generate vector representations of new documents
new_doc = word_tokenize("This is a new document.")
vector = model.infer_vector(new_doc)
```
In this example, we create a corpus of three documents and train a Doc2Vec model with a vector size of 100, a window size of 5, a minimum word count of 1, and 50 epochs. We then generate a vector representation of a new document using the `infer_vector` method.