principal component analysis on centered-standardized data
model=cspcana(x)
a matrix (n x q) or a Div structure
a structure containing the following fields:
model.scores: scores of the observations onto the eigenvectors
model.eigenvec: eigenvectors or loadings
model.var_scores: scores of the variables onto the eigenvectors
model.eigenval: eigenvalues
model.x_mean: mean vector of the columns of x
model.x_stdev: standard-deviations vector of the columns of x (calculated with (n-1))
model.centred: 1=x centred
model.std: 1=x standardized