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主成分分析过程是不是可以认为是消除自变量相关性的过程？或者是其作用之一？

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关键词：主成分分析 主成分 自变量相关 自变量 相关性 主成分分析 主成分分析法 spss主成分分析 逐步回归分析 多元回归分析 因子分析法 应用时间序列分析

是的，根据自变量之间的相关性进行降维处理

http://en.wikipedia.org/wiki/Principal_component_analysis

Principal component analysis (PCA) involves a mathematical procedure that transforms a number of possibly correlated variables into a smaller number of uncorrelated variables called principal components. The first principal component accounts for as much of the variability in the data as possible, and each succeeding component accounts for as much of the remaining variability as possible. Depending on the field of application, it is also named the discrete Karhunen–Loève transform (K.L.T.), the Hotelling transform or proper orthogonal decomposition (POD).

PCA was invented in 1901 by Karl Pearson.[1] Now it is mostly used as a tool in exploratory data analysis and for making predictive models. PCA involves the calculation of the eigenvalue decomposition of a data covariance matrix or singular value decomposition of a data matrix, usually after mean centering the data for each attribute. The results of a PCA are usually discussed in terms of component scores and loadings (Shaw, 2003).

PCA is the simplest of the true eigenvector-based multivariate analyses. Often, its operation can be thought of as revealing the internal structure of the data in a way which best explains the variance in the data. If a multivariate dataset is visualised as a set of coordinates in a high-dimensional data space (1 axis per variable), PCA supplies the user with a lower-dimensional picture, a "shadow" of this object when viewed from its (in some sense) most informative viewpoint.

PCA is closely related to factor analysis; indeed, some statistical packages deliberately conflate the two techniques. True factor analysis makes different assumptions about the underlying structure and solves eigenvectors of a slightly different matrix.

我认为是的。

根据自变量之间的相关性进行降维处理
相当于抽出几个共同成分达到降维的目的~~

將原些一些有相關性的變量，重新線性組合成獨立變量，並以variance(F1)最大者之主成分為第一主成分，也有人考慮主成分中各原有變量之權重大小，來縮減變數個數；一般主成分之個數會比原變量個數還少，但解釋能力不會被降低過多。