Pcoa yog dab tsi?
Pcoa yog dab tsi?

Video: Pcoa yog dab tsi?

Video: Pcoa yog dab tsi?
Video: Yog hmoov dab tsi - Gao Nou Kue ft. Mang Vang (Official Music Video) New song 2020 2024, Kaum ib hlis
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PCOA yog ib tug scaling los yog ordination txoj kev uas pib nrog ib tug matrix ntawm zoo sib xws los yog dissimilarities ntawm ib pawg ntawm cov tib neeg thiab aims los tsim ib tug tsawg-dimensional graphical zajlus ntawm cov ntaub ntawv nyob rau hauv xws li ib tug txoj kev uas deb ntawm cov ntsiab lus nyob rau hauv cov zajlus yog ze rau thawj dissimilarities.

Ib yam li ntawd, PCoA tsom xam yog dab tsi?

Thawj Tswj Hwm Coordinates Kev tsom xam ( PCOA , = Multidimensional scaling, MDS) yog ib txoj hauv kev tshawb nrhiav thiab pom qhov zoo sib xws lossis qhov sib txawv ntawm cov ntaub ntawv. Nws pib nrog qhov zoo sib xws matrix lossis dissimilarity matrix (= matrix nrug) thiab muab rau txhua yam khoom ib qho chaw nyob rau hauv qhov chaw qis, piv txwv li. raws li 3D graphics.

Kuj Paub, dab tsi yog qhov kev txiav txim siab? Ib tug coenocline yog ib tug graphical sawv cev ntawm tag nrho cov lus teb functions ntawm hom nyob rau hauv lub zej zog npaj raws li ib tug ib puag ncig gradient. Muab ntau hom thiab lub suab nrov hauv kev tshawb fawb feem ntau, coenoclines feem ntau tsuas yog tso tawm hauv daim ntawv yooj yim heev.

Qhov thib ob, qhov txawv ntawm PCA thiab PCoA yog dab tsi?

Thaum PCA yog nyob ntawm Euclidean nrug, PCOA muaj peev xwm lis (dis) zoo sib xws matrices xam los ntawm quantitative, semi-quantitative, qualitative, thiab mixed variables. Raws li ib txwm muaj, qhov kev xaiv ntawm (dis) qhov zoo sib xws ntsuas yog qhov tseem ceeb thiab yuav tsum haum rau cov ntaub ntawv hauv nqe lus nug.

Dab tsi yog metric multidimensional scaling?

Tsis yog - metric multidimensional scaling (NMDS) yog ib txoj hauv kev tsis ncaj qha gradient tsom xam uas ua rau muaj kev tswj hwm raws li qhov kev ncua deb lossis qhov sib txawv ntawm matrix. Txhua qhov sib txawv coefficient lossis qhov ntsuas qhov deb yuav raug siv los tsim qhov kev ncua deb matrix siv los ua cov tswv yim. NMDS yog ib txoj hauv kev raws qib.

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