Population structure
Overview
We will estimate population structure in the beef cattle data.
Load R objects
Use the function load()
to load the results from genomic BLUP day20.Rda we created in class.
load(file.choose()) # day20.Rda
Calculate eigenvectors and eigenvalues
We will use the function eigen
to perform an eigen decomposition of the \(\mathbf{G}\) matrix.
ed <- eigen(G)
# eigen values
head(ed$values)
# eigen vectors
dim(ed$vectors)
PC1 vs. PC2
plot(ed$vectors[, 2], ed$vectors[, 1])
PC1 vs. PC3
plot(ed$vectors[, 3], ed$vectors[, 1])
PC2 vs. PC3
plot(ed$vectors[, 3], ed$vectors[, 2])