is psych's principal function pca is the principle function still pca in pca why is it important to get pca from spss is psych's principal function still pca does psych use rotation in r does pca always work after rotation why do you use pca in r what is the function of psych is psych pca which is a parameter used to do pca when pca is used what parameters is it does psych have pca in r what is the function for psych what is principle in psyc are psys always pca is pca a function of spps psych principal function still pca is rotation still pca why does pca r how to use pca function