Cov ntsiab lus tseem ceeb muaj ntau yam khoom muaj txiaj ntsig (Rao 1964; Kshirsagar 1972): Cov eigenvectors yog orthogonal, yog li cov ntsiab lus tseem ceeb sawv cev rau kev sib koom ua ke los ntawm qhov chaw ntawm qhov hloov pauv qub. Cov ntsiab lus tseem ceeb ntawm cov qhab nia yog sib koom ua ke tsis cuam tshuam
Puas yog cov ntsiab lus tseem ceeb cuam tshuam?
Principal Cheebtsam tsom xam yog raws li kev sib txheeb matrix ntawm qhov sib txawv ntawm qhov sib txawv, thiab kev sib raug zoo feem ntau xav tau tus qauv loj ua ntej lawv ruaj khov.
PCA Cheebtsam puas muaj kev ywj pheej?
PCA ua haujlwm cov ntaub ntawv rau hauv qhov chaw tshiab uas tau nthuav tawm los ntawm cov khoom tseem ceeb (PC), uas tsis sib xws thiab orthogonal. Cov PCs tuaj yeem ua tiav cov ntaub ntawv tseem ceeb hauv cov ntaub ntawv. … Cov Cheebtsam no yog cov txheeb cais ywj pheej, piv txwv li tsis muaj cov ntaub ntawv sib tshooj ntawm cov khoom.
Puas yog lub ntsiab lus tseem ceeb tshwj xeeb?
Tom qab ntawd hauv 1 seem PCA, peb pom ib txoj kab los ua kom qhov sib txawv ntawm qhov kev kwv yees ntawm 2 qhov ntev ntawm cov ntaub ntawv mus rau kab ntawd. … Cov kab no tsis yog tshwj xeeb thaum 2D cov ntaub ntawv muaj kev sib hloov symmetry, yog li muaj ntau tshaj ib kab uas muab tib qhov sib txawv ntawm qhov kev kwv yees.
Puas yog cov khoom tseem ceeb ntawm orthogonal?
Cov khoom tseem ceeb yog eigenvectors ntawm covariance matrix, thiab yog li lawv yog orthogonal. Qhov tseem ceeb, cov ntaub ntawv uas siv cov txheej txheem PCA yuav tsum tau ntsuas. Cov txiaj ntsig kuj tseem ceeb rau qhov txheeb ze qhov ntsuas.