the necessity of dimensionality reduction
1. Multi-collinearity--predictor variables are interconnected. Multiple collinearity causes instability in the solution space, which can lead to incoherent results.
2. The high-dimensional space itself is sparse. One-dimensional normal distribution has a value of 68% falling between the positive and negative standard deviations, and only 0.02% in 10-dimensional space.
3. Too many variables can hinder the establishment of a search rule.
4. Analysis
Org. apache. hadoop. filecache-*, org. apache. hadoop
I don't know why the package is empty. Should the package name be a class for managing File Cache?
No information was found on the internet, and no answers were answered from various groups.
Hope a Daniel can tell me the answer. Thank you.
Why is there no hadoop-*-examplesjar file after the hadoop standalone configuration platform is set up?
The PLSA model is based on the idea of frequency, each document's K-theme is fixed, each topic of the word probability is also fixed, we ultimately require a fixed topic-word probability model. Bayesian School Obviously does not agree, they believe that the subject of the document is unknown, the topic of the distribution of words is not known, we can not solve the exact value, can only calculate doc-topic probability model, topic-word probability model of probability distribution.LDA Model Docu
http://blog.csdn.net/pipisorry/article/details/45307369LDA limitations:what ' s next?Although LDA is a great algorithm for topic-modelling, it still have some limitations, mainly due to the fact that it's has Become popular and available to the mass recently. One major limitation is perhaps given by its underlying unigram text model : LDA doesn ' t consider themutual position of the words in the document.
Reprinted from WentingtuTopic model deformation based on LDA in recent years, with the emergence and development of LDA, a group of topic model cattle have sprung up. My main focus is on the following Daniel and his students:Founder of David M. Bleilda, PhD graduated in 04. A doctoral dissertation on topic model fully embodies its profound mathematical probabilistic skills, and its own implementation of
Http://blog.csdn.net/hexinuaa/article/details/6021069
Over the past few years, along with the emergence and development of LDA, a group of talented people have emerged to create topic models. I mainly pay attention to the following Daniel and his students:Founder of David M. bleilda, Ph.D. in 04 years. A doctoral thesis on topic model fully embodies its profound mathematical probability knowledge, and its own
Four machine learning dimensionality reduction algorithms: PCA, LDA, LLE, Laplacian eigenmapsIn the field of machine learning, the so-called dimensionality reduction refers to the mapping of data points in the original high-dimensional space to the low-dimensional space. The essence of dimensionality is to learn a mapping function f:x->y, where x is the expression of the original data point, which is currently used at most in vector representations. Y
In speech recognition, in order to enhance the robustness of audio features, it is necessary to extract the characteristic vectors with strong distinguishing ability, and the common method is PCA and LDA algorithm.
The PCA algorithm seeks to preserve the most effective and important component of the data, leaving out some redundant components that contain less information.
LDA is a change matrix to achiev
The weekend was a little experiment at home with LDA for two days. Among the many implementations of LDA's toolkit, Gibbslda is the most widely used, including the C + + version, the Java version, and so on. Gibbslda++ is the implementation of its C + + version, which is currently available in version 0.2. During the actual use, the implementation version was found to have memory usage issues. I took some time to locate the problem and put it up for e
Preparing for the TOEFL test during the summer vacation, and having no time to organize blogsArticleAnd reply to comments. I hope some friends will forgive me. Starting from September, this blog began to focus on topic modeling and LDA probability models, and studied PRML, a classic book of machine learning. This book does not yet have a Chinese translation version, so it can only chew on the original English version, higher quality of the original ve
Themed Modeling A method of finding abstract art subject art in a large number of documents. With it, it is possible to discover a mix of hidden or "latent" topics that vary from one document in a given corpus . As an unsupervised machine learning method, the topic model is not easy to evaluate because there is no marked "basic facts" data available for comparison. However, because topic modeling often requires some parameters to be predefined (first, the topic to be discovered ? ). , so mod
Objective
LDA linear discriminant Analysis, also known as linear discriminant vector, it is Ronald Fisher invented, so sometimes called Fisher identification vector, its nuclear version is called KFDA (Kernel Fisher discriminant analysis).
Classification Problem of machine learning, is a supervised learning. The so-called supervision is the type of training samples. As the name implies, unsupervised learning is no sample of the category information,
result.discriminant analysis, unlike PCA, does not want to keep the most data, but wants the data to be easily distinguishable after dimensionality reduction. The method of LDA is introduced later, and is another common linear dimensionality reduction method. In addition, some nonlinear dimensionality reduction methods can be used to distinguish the results, such as Lle,laplacian Eigenmap, by using the local properties of data points. will be introdu
, does not want to keep the most data, but wants the data to be easily distinguishable after dimensionality reduction. The method of LDA is introduced later, and is another common linear dimensionality reduction method. In addition, some nonlinear dimensionality reduction methods can be used to distinguish the results, such as Lle,laplacian Eigenmap, by using the local properties of data points. will be introduced later.LdaLinear discriminant analysis
Latent Dirichlet Allocation (LDA) is a thematic model that enables the modeling of text and the distribution of the subject matter of the document. The commonly used model parameter estimation method has Gibbs sampling and variational inference, there are many introductions about LDA on the net, the most classic such as "Lda math gossip" of Rickjin. The purpose o
1. Basic knowledge of LDALDA (latent Dirichlet Allocation) is a thematic model. LDA a three-layer Bayesian probabilistic model that contains the word, subject, and document three-layer structures.LDA is a build model that can be used to generate a document that, when generated, chooses a topic based on a probability, then a word in the subject of probability selection, so that a document can be generated, and in turn,
Transferred from: http://blog.csdn.net/kklots/article/details/8247738
Recently, as a result of the curriculum needs, has been studying through the face to judge gender, in the OPENCV contrib provides two methods that can be used to identify gender: Eigenface and Fisherface,eigenface mainly using PCA (principal component analysis), By eliminating the correlation in the data, the high-dimensional image is reduced to the low-dimensional space, the sample in the training set is mapped to a point in
different, the updated area is different, when the parallel loop calculation of Word is not affected, when the parallel loop calculates the same word, just need to accumulate the results of the calculation, also OK(3) The vector of the distribution of word on each topic, this result will be affected. For example, if the training data is divided into two parts, the two copies found two word (usually different), to update the above vector, and this vector write operation if not protected, will wr
Read the first few sections of a little tail Dirichlet distribution 1 Review beta distribution 2 Dirichlet distribution Dirichlet distribution derivation of beta distribution and Dirichlet distribution 3 How to better understand this distribution
0. Read the instructions
The necessary and minimal knowledge that is closely related to LDA is the body of the blog post. The contents of the gray box are expanded and supplemented, and skipping directly wi
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.