This should be very basic and I hope someone can help me. I ran a principal component analysis with the following call:
pca <- princomp(....)
summary(pca)
Summary pca returns this description:
PC1 PC2 PC3
Standard deviation 2.8788 2.7862 2.1845
Proportion of Variance 0.1977 0.1549 0.07831
Look at the second line which shows the variance explained by each PC. How can I programmatically extract this vector in my script from the variable pca. I have done enough search and cannot find an answer.
Proportion of Variance is nothing else than normalized standard deviations. You can calculate them as PoV <- pca$sdev^2/sum(pca$sdev^2)