# Normalizing all the variarbles vs. using scale=TRUE option in prcomp in R

What is the difference between

1. normalizing the variables and doing PCA;
2. using scale=TRUE option (without normalizing the variables) in prcomp function in R?
• I erased your last sentence/paragraph because it was very hard to understand while your question is very clear already without it. – amoeba Mar 18 '17 at 15:59

No difference. Type debug(prcomp) before running prcomp. The third line of the function reads: x <- scale(x, center = center, scale = scale.); ie. you will either scale within the function if you set scale = TRUE during function call or you will have the scaling done originally by you.