If i is "data", returns a list with the following elements:
data 
A numeric matrix of raw data.
mean 
A numeric vector giving the variables means (PCA).
sd 
A numeric vector giving the variables standard deviations
(PCA).
If i is "rows", returns a list with the following elements:
coord 
A numeric matrix of rows/individuals coordinates.
cos2 
A numeric matrix of rows/individuals squared cosine.
masses 
A numeric vector giving the rows masses/individual
weights.
sup 
A logical vector specifying whether a point is a
supplementary observation or not.
If i is "columns", returns a list with the following elements:
coord 
A numeric matrix of columns/variables coordinates.
cor 
A numeric matrix of correlation between variables and
the dimensions (PCA).
cos2 
A numeric matrix of columns/variables squared cosine.
masses 
A numeric vector giving the columns masses/variable
weights.
sup 
A logical vector specifying whether a point is a
supplementary observation or not.
If i is "eigenvalues", returns a numeric vector of eigenvalues.