principal component analysis python

I. INTRODUCTION of PCA 1. Related background Principal component Analysis (Principal Component ANALYSIS,PCA) is a statistical method. An orthogonal transformation transforms a set of variables that may be related to a set of linea

Principal Component Analysis (PCA) is a multivariate statistical analysis method that uses linear transformation to select a small number of important variables. It is also called Main Component analysis. In practice, many variabl

1.PCAUsage Scenario: Principal component analysis is a data dimensionality reduction that converts a large number of related variables into a small set of unrelated variables called principal components.Steps: Data preprocessing (guaranteed no missing values in the data) Select a factor model (whether PCA

expression:The expression of the above-loaded J is obtained:Then using the Laplace multiplier (a little bit here), we can get the expression of the projection base we want:Here is another characteristic value expression, we want the first m vector is actually here the largest m eigenvalues corresponding to the eigenvector. Prove this can also see, we J can be translated into:That is, when the error J is composed of the smallest d-m eigenvalues, J obtains the minimum value. It's the same as the

expression:The expression of the above-loaded J is obtained:Then using the Laplace multiplier (a little bit here), we can get the expression of the projection base we want:Here is another characteristic value expression, we want the first m vector is actually here the largest m eigenvalues corresponding to the eigenvector. Prove this can also see, we J can be translated into:That is, when the error J is composed of the smallest d-m eigenvalues, J obtains the minimum value. It's the same as the

expression:The expression of the above-loaded J is obtained:Then using the Laplace multiplier (a little bit here), we can get the expression of the projection base we want:Here is another characteristic value expression, we want the first m vector is actually here the largest m eigenvalues corresponding to the eigenvector. Prove this can also see, we J can be translated into:That is, when the error J is composed of the smallest d-m eigenvalues, J obtains the minimum value. It's the same as the

History of principal component analysis:Pearson was proposed in 1901 and then developed by Hotelling (1933) as a multivariate statistical method. Through the main components of the analysis to show the largest individual differences, but also to reduce the number of regression analysis and clustering variables, you can

calculation is used in many places, such as image recognition, PageRank, Lda, and PCA, which will be mentioned later. It is a feature face that is widely used in image recognition. Feature face extraction has two purposes: first, to compress data. For an image, you only need to save the most important part, and thenProgramIt is easier to process. When extracting the main features, a lot of noise is filtered out. The role of PCA is very relevant. There are many methods to evaluate the fe

indicators will lose a lot of information, easy to produce erroneous conclusions. It is therefore necessary to find a reasonable way to minimize the loss of information contained in the original indicator while minimizing the need for analysis in order to achieve the objective of a comprehensive analysis of the data collected. Because there is a certain correlation between the variables, it is possible to

interested in the average luminance value of an image block, so we can subtract this value to make the mean normalized.The specific step is that if you represent the luminance (grayscale) value () of a 16x16 image block, you can use the following algorithm to perform a 0-value operation on each image:, for allPlease note: 1) for each input image block to perform the above two steps, 2) here is the average luminance value of the image block. It is particularly important to note that this and the

Abstract: PCA (principal component analysis) is a multivariate statistical method. PCA uses linear transformation to select a small number of important variables. It can often effectively obtain the most important elements and structures from overly "rich" data information, remove Data Noise and redundancy, and reduce the original complex data dimension, reveals

dimensionality reduction (i)----the source of principal component analysis (PCA)Reduced Dimension Series: dimensionality reduction (i)----the source of principal component analysis (PCA) dimensionality Reduction (ii)-

Module Name: pca.pyPCA principle and the principle of tightening techniques to be mended ...#-*-coding:utf-8-*-" "Created on March 2, 2015 principal component analysis of p-14 image of @author:ayumi Phoenixch01" " fromPILImportImageImportNumPydefPCA (X):"""principal component