I have performed a scaled and centred PCA on a dataset with nine variables. I now want to quantify the contribution of each factor to the PCA.
Using a scree plot, I have identified that only the first three PCs are required.
My question is: if for each of the three PCs, I **multiply each rotation score by the PCs % explained **, and then sum this across all three PCs, will I be able to compare the 'overall' contribution of a variable to the PCA?
I am working in R, E.g.
pca <- prcomp(data, scale=TRUE)
percents <- pca$sdev^2 / sum(pca$sdev^2)
overall <- (abs(pca$rotation[, 1]) * percents[1]) +
(abs(pca$rotation[,2]) * percents[2]) + (abs(pca$rotation[,3]) *
percents[3])
Would these scores be a valid way to compare a factor's contribution? Do they have a name?