Http://www.ruanyifeng.com/blog/2013/03/tf-idf.htmlApplication of TF-IDF and cosine similarity (i): Automatic extraction of keywordsHttp://www.ruanyifeng.com/blog/2013/03/cosine_similarity.htmlApplication of TF-IDF and cosine similarity (II.): Finding similar articlesHttp://www.ruanyifeng.com/blog/2013/03/automatic_summarization.htmlApplication of TF-IDF and cosin
Before parsing the Lucene search process, it is necessary to separate the Lucene score formula and describe the meaning of each part. Because of Lucene's search process, a very important step is to gradually calculate the scores of each part.
Lucene's scoring formula is very complex, as follows:
Before derivation, we will introduce the meaning of each part one by one:
T: Term. The Term here refers to the Term that contains the domain information, that is, the title: hello and content: hello
code, and deploy the Lucene-driven full-text search cluster. You will find it works very well, fast and accurate.Then you wonder: Why is Lucene so awesome?This article, which focuses on Tf-idf,okapi BM-25 and the general relevance score, and the next article (main introduction index) will tell you the basic concepts behind full-text search.CorrelationFor each search query, it is easy to define a "related score" for each document. When a user makes a
, functional words have no practical meaning, such as "the", "is", "at", "which" and so on. Another category is lexical words, such as "want" and so on. Discontinued words have no meaning for the sentiment classification of movie reviews, so we need to delete some of the discontinued words. Use the Nltk.download function to get the deactivation words provided by NLTK and to remove the deactivation words from the movie comments using these deactivation words. The NLTK library provides a total of
linguistic term that is synonymous with stemming (stemming), which can be called word-of-word reduction , which is to restore "drove" to "drive" by querying the dictionary.And stemming will shorten the word, "apples", "apple" after processing has become "APPL"
Wikipedia introduction to Word-of-word reduction
European languages Lemmatizer A C-language Lib
Do computer language study will involve lemmatization, I personally think do search completely can not consider, stemming al
Brief introductionView Baidu Search 中文文本聚类 I am disappointed to find that there is no complete online on the python implementation of the Chinese text clustering (and even search keywords python 中文文本聚类 are so), the Internet is mostly about the text clustering Kmeans 原理 , Java实现 R语言实现 ,, There's even one C++的实现 .I wrote some of the articles, I did not very good classification, I would like to be able to cluster the method of some similar articles to cluster, and then I look at each cluster of the
sequencingThe first part: VSMThe VSM is referred to as vector space model, which is mainly used to calculate the similarity of documents. When calculating document similarity, important features need to be extracted. Feature extraction generally uses the most general general method: TF-IDF algorithm. This method is very simple but very practical. Give you an article, with the Chinese word breaker tool (currently the best is the OPENNLP community in t
1.Feature extractors (feature extraction)
1.1 TF-IDF
Word frequency (term Frequency)-reverse document frequencies (inverse documents Frequency) is a feature vectorization method that is widely used in text mining to assess the importance of a term to one file set or one document in a corpus. Definition: T is represented by a word, D represents a document, D represents a corpus of multiple documents (corpus), and Word frequency TF (t,d) indicates how
, and scatter the flowers! When the database is not large, it is okay.
But when you have more and more data, you will find that your database is getting slower and slower. MySQL is not a very useful full-text search tool. Therefore, you decided to use ElasticSearch to refactor the code and deploy the Lucene-driven full-text search cluster. You will find that it works very well, fast and accurate.
Then you may wonder: why is Lucene so awesome?
This article (mainly about TF-
words, each of which has a Weight (Term Weight ), different words affect the importance of Relevance Based on their weights in the document.Document = {term1, term2 ,...... , TermN}Document Vector = {weight1, weight2 ,...... , WeightN}
Where ti (I =,... n) is a column of different words, and wi (d) is the weight of ti in d.
When selecting feature words, you need to reduce the dimension to select representative feature words, including manually selected or automatically selected.
Step 2, TF-
Elasticsearch, refactor the code, and deploy the Lucene-driven full-text search cluster. You'll find it works very well, fast and accurate.
Then you wonder: Why is Lucene so cool?
This article (mainly about Tf-idf,okapi BM-25 and the general relevance score) and the next article (main introduction index) will tell you the basic concepts behind full-text search.
Correlation
For each search query, it is easy to define a "related score" for each doc
I got it from google and Baidu and at for a long time ......, Hope to help you.
Let's look at the code ......
Image:
Init: function (uuid) {// this. identifier is the set global variable, and uuid is the unique encoding during page loading this. identifier = uuid; // Image Upload var idf = this. identifier; var that = this; $ ('#' + idf + '-tform '). ajaxForm ({dataType: 'json', beforeSubmit: funct
1 in one vector is no longer the same as the value in another vector.
Why do we care about this standardization? Considering this situation, if you want to make a document look more relevant to a specific topic than it actually does, you may repeatedly repeat the same word, to increase the possibility of including a topic. Frankly speaking, to some extent, we get a result that degrades the information value of the word. Therefore, we need to scale down the values of words that frequently appear
introductory process.One: Win environmentI direct download of the An integrated development environment of the esp8266 (previously the letter was Ann can, so looked for a bit, sure enough to support ESP32). Ann can then find the development environment below: How to install an integrated development environment, how to use the integrated development environment of the Aisin ESP series, how to burn the firmware for ESP series moduleClick in, follow the tutorial to download the file of the netw
Termquery rewrite = this "wdx"1. getweight ProcessInstantiate a termweight with the following attributes:Float value-IDF * boost/Math. SQRT (IDF * boost * IDF * boost)Float IDF-term in index IDFFloat querynorm-1.0/Math. SQRT (IDF * boost *
interconnectivity of networks
· Information extraction IE: identifies and extracts relevant facts and relationships from unstructured texts; and extracts structured data from unstructured or semi-structured texts.
· Natural language processing (NLP): discovering the structure and meaning of language essence from the perspective of syntax and semantics
Text Classification System (python 3.5)
The text classification technology and process of Chinese language mainly includes the following steps:
, you can see right away that we scaled down the vectors in a proportional way so that each of their elements is between 0 and 1 and does not lose much valuable information. You see, a word with a count of 1 is no longer the same as the value in one vector and its value in another.
Why do we care about this standardization? Considering this, if you want a document to look more relevant to a particular topic than it actually is, you might increase the likelihood that it will be included in a sub
Address: https://en.wikipedia.org/wiki/Okapi_BM25In information retrieval, okapi BM25 (BM stands for best Matching) is a ranking function used by search engines T o Rank matching documents according to their relevance to a given search query. It is based on the probabilistic retrieval framework developed in the 1970s and 1980s Bystephen E. Robertson, Karen Spärck Jones, and others.The name of the actual ranking function is BM25. To set the right context, however, it usually referred to as "Okapi
Emotional analysis based on social network Iiiby white Shinhuata (http://blog.csdn.net/whiterbear) reprint need to indicate the source, thank you.In front of the micro-Bo data capture, simple processing, this article on the school Micro-blog similarity analysis.Similarity analysis of WeiboThis is an attempt to calculate the similarity between any two schools ' microblog words.Idea: First of all, the school micro-bo participle, traverse to get each school's high-frequency Dictionary of words, set
bootloader file of this project is supported by bootloader \ subproject \ main \ bootloader_start.c under the component directory in esp-idf. view Source Code ), after the SoC is reset, the pro cpu runs immediately and executes the Reset vector code, while the app cpu remains reset. During startup, the pro cpu executes all initialization.call_start_cpu0The CPU reset of the APP in the APP startup code is canceled. The Reset vector code is located in t
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.