Analysis (PCA): in this technique, variables is transformed into a new SE t of variables, which is linear combination of original variables. These new set of variables is known as principle components. theyare obtained in such a-the-first principle component accounts for most of the possible variation of O Riginal data after Whicheach succeeding component have the highest possible variance. The second principal component must is orthogonal to the
Linear discriminant Analysis (Linear discriminant Analyst) (i)1. QuestionsBefore we discussed the PCA, ICA or the sample data to say, can be no category tag Y. Recall that when we do the regression, if there are too many features, then there will be irrelevant features introduced, over-fitting and so on. We can use PCA to reduce dimensions, but PCA does not take
? can be differentiated ? accuracy ? quantity and efficiency ? invariance Local feature extraction algorithm-sift ? The SIFT algorithm was put forward by D.g.lowe 1999 and summarized in 2004. Later y.ke the description of the sub-section using PCA to replace the histogram of the way it was improved. ? Sift algorithm is an algorithm for extracting local features, searching for extreme points in scale space, extracting position, scale and rotation inva
)1.707825127659933or accept a row, the operation of a column, by the parameter Axis=1 (row) or axis=0 (column) to control, such as:>>> C.mean (1)Array ([1.5, 3.5, 5.5])>>> C.mean (0)Array ([3., 4.])Linear algebra1. Use dox to multiply the matrix, as>>> A=np.array ([[5,7,2],[1,4,3]])>>> AArray ([[5, 7, 2],[1, 4, 3]])>>> B=np.ones (3)>>> bArray ([1., 1., 1.])>>> A.dot (b)Array ([14., 8.])Or:>>> Np.dot (a, B)Array ([14., 8.])A is the 2*3 array, B is the 3*1 array, then A.dot (b) is clearly the 2*1
frame.650) this.width=650; "src=" https://s1.51cto.com/wyfs02/M01/8E/D5/wKiom1jLsyHTk8TEAABMiyNINPY891.jpg "title=" 2.jpg "alt=" Wkiom1jlsyhtk8teaabmiyninpy891.jpg "/>Three. VLAN communication1. Internal communication within the same VLAN1 ports and 4 ports in the switch belong to the same VLAN, the PCA sends the MAC address of the ARP request PCB, the data frame is vlan2 on the switch 1, and forwards the ARP broadcast within the VLAN2, the data fram
sharing the Internet with this method in the same dorm.As to why IP conflicts are not caused and can also be Internet, this is because of the shortcomings of ARP work, the system will find the network has a phase of the IP and prompt "IP conflict", because the system at startup, TCP/IP arp will broadcast a free ARP request packet to the network segment, This arp (free ARP) package contains its own IP and Mac, if the network segment has a response to the packet, the broadcast of the machine will
, and to classify non-identical (or distant) samples in other classes.10) Principal component analysis (Principal Component ANALYSIS,PCA)Principal component analysis is to find the principal component by using orthogonal transformations to convert some of the column's potentially related data into linearly unrelated data. The most famous application of PCA method is the feature extraction and data dimension
building the model ... generating ... Writing data to deepid_test/0.pklloading data of VEC_TEST/3.PKL building the Model ... generating ... Writing data to deepid_test/3.pklloading data of VEC_TEST/1.PKL building the Model ... generating ... Writing data to deepid_test/1.pklloading data of VEC_TEST/7.PKL building the Model ... generating ... Writing data to Deepid_test/7.pklThe program extracts each file within the Vectorization folder and obtains the correspond
The main reference is the articleHttp://www.cnblogs.com/LeftNotEasy/archive/2011/01/08/lda-and-pca-machine-learning.htmlHttp://www.cnblogs.com/jerrylead/archive/2011/04/21/2024384.htmlHttp://www.cnblogs.com/jerrylead/archive/2011/04/21/2024389.htmlThe above three blogs have been summed up very well:Here we summarize the most important part:the principle of LDA is that The data that will be tagged (points) , projection to the lower dimension of the spa
First, the question:If we now have two machines: PCA and PCB, now we want to allow ServerA to access without entering a password. two method and principle: You can use ssh-keygen-t RSA to generate private and public keys on the PCA and copy the generated public key to the remote machine PCB On the back,You can use the SSH command to log on to another machine PCB without a password.In a Linux system,
Although the neural network has a very complete and useful framework, and BP Neural network is a relatively simple and inefficient one, but for the purpose of learning to achieve this neural network is still meaningful, I think.
The following program uses the iris dataset, in order to facilitate the drawing first with PCA to the data to reduce the dimension. At the same time, the classification results are labeled, according to the characteristics of
Original URL:
Http://www.bo-yang.net/2014/04/30/fisher-vector-in-action-recognition
This is a summary of doing human action recognition using Fisher vectors with (improved) dense trjectory Features (DTF, HTTP ://lear.inrialpes.fr/~wang/improved_trajectories) and STIP features (http://crcv.ucf.edu/ICCV13-Action-Workshop/ download.html) on UCF 101 DataSet (http://crcv.ucf.edu/data/UCF101.php). In the STIP features, the low-level visual features HOG and HOF is integrated, with dimensions and resp
feature data set, is a contained relationship, not change the original feature space.
3. Feature extraction:
Principal component Analysis (Principle, PCA) and linear evaluation analysis (Linear discriminant Analysis,lda) are two of the main classical methods for feature extraction .
1.. PCA V.s LDA
For feature extraction, there are two categories:
(1) Signal representation (signal indication): The
contour coefficients to measure the quality of the clustering results. The contour factor also takes into account the aggregation degree and the degree of separation of the cluster.Used to evaluate the effect of clustering and take a range of values [ -1,1]. The larger the value of the contour system, the better the clustering effect.K-Clustering algorithm two major defects ① easily convergent local optimal solution ② need to set the number of clusters beforehandUse the Elbow observation method
Principal component Analysis R software implementation program (i):>d=read.table ("clipboard", header=t) #从剪贴板读取数据>sd=scale (d) #对数据进行标准化处理>SD #输出标准化后的数据和属性信息, copy standardized data to clipboard backup>d=read.table ("clipboard", header=t) #从剪贴板读取标准化数据>pca=princomp (d,cor=t) #主成分分析函数>screeplot (pca,type= "line", mian= "gravel chart", lwd=2) #画出碎石图From the gravel map can be seen, the first two principal comp
triangle gridAssuming that the z-axis in the coordinate system of the human triangle mesh is the direction vector of the midpoint of the human Horn and the center of the head, the coordinate system of the triangle mesh obtained by the handheld scanner depends on the orientation of the first scan, so that the z-axis of the grid has an error with the correct coordinate system.The core method used in this paper is PCA (Principal Component analysis). For
parameter adjustments, greater risk of overfitting
The dimension used to solve the actual problem may be virtual high
The less dimension means that the faster you train, the more you can try.
Visualization of
Dimensionality reduction Method: Feature selection method and feature extraction method. Generate, analyze, and then discard some features.
Principal component analyses (Principal Component analysis, PCA), linea
Select Attributes (Weka's book to translate features into attributes, then the attributes here are actually referred to as features)The purpose of selecting attributes:is by searching all the possible combinations of attributes in the data to find the best subset of attributes to predict.That is, assuming that the attribute currently has 6, the accuracy rate is 80%, assuming that only 5 attributes (this is a subset), but the accuracy rate is changed to 90%
The selection attribute is different fr
lazy Learning Algorithm
Summary
Chapter 4 build a good training set-data preprocessing
Process Missing Values
Remove features or samples with missing values
Rewrite Missing Value
Understanding the estimator API in sklearn
Process classified data
Splits a dataset into a training set and a test set.
Unified feature value range
Select meaningful features
Evaluate feature importance using random Forest
Summary
Chapter 5 compressing data by Dimensionality
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