> PCA1 = princomp(Allct[,5:12])

> as<-summary(PCA1)

> as

Importance of components:

? ?? ?? ?? ?? ?? ?? ?? ???Comp.1? ???Comp.2? ???Comp.3? ?? ?Comp.4? ?? ?Comp.5? ?? ? Comp.6 Comp.7 Comp.8

Standard deviation? ???0.7878720 0.21805719 0.12375431 0.056224281 0.033734326 4.222699e-10? ?? ?0? ?? ?0

Proportion of Variance0.90236560.06912133 0.02226342 0.004595355 0.001654304 2.592098e-19? ?? ?0? ?? ?0

Cumulative Proportion??0.9023656 0.97148692 0.99375034 0.998345696 1.000000000 1.000000e+00? ?? ?1? ?? ?1

>

> 怎樣提取第一主成分解釋變異數(shù)值，即提取數(shù)值0.9023656，用哪個命令提取？

其實一條代碼就可以計算出

assev^2/sum(as sdev^2)[1]