What is loadings and SS loadings signifies in factor analysis

r
factor_analysis

#1

I was solving one factor analysis question and I have find the factor using PCA and I have used in model but when I have looked at the model I found to terms loadings and SS loadings I am not able to understand what this two helps to get better knowledge of the model.

library(lattice)

z <- mtcars
pairs(z)
my <- prcomp(z, center=TRUE, scale=TRUE)
screeplot(my, main=“Scree Plot”, xlab=“Components”)
screeplot(my, main=“Scree Plot”, type=“line” )
my_f1<-factanal(z,factor=3,rotation=“varimax”)

Call:
factanal(x = z, factors = 3, rotation = “varimax”)

Uniquenesses:
mpg cyl disp hp drat wt qsec vs am gear carb
0.135 0.055 0.090 0.127 0.290 0.060 0.051 0.223 0.208 0.125 0.158

Loadings:
Factor1 Factor2 Factor3
mpg 0.643 -0.478 -0.473
cyl -0.618 0.703 0.261
disp -0.719 0.537 0.323
hp -0.291 0.725 0.513
drat 0.804 -0.241
wt -0.778 0.248 0.524
qsec -0.177 -0.946 -0.151
vs 0.295 -0.805 -0.204
am 0.880
gear 0.908 0.224
carb 0.114 0.559 0.719

           Factor1 Factor2 Factor3

SS loadings 4.380 3.520 1.578
Proportion Var 0.398 0.320 0.143
Cumulative Var 0.398 0.718 0.862