Loading plot of the variables from a Principal Components Analysis. scores of the observations are surimposed
data_biplot(X, sX = TRUE, axeh = 1, axev = 2, cex.lab = 1)
the data matrix
TRUE/FALSE : standardization or not of the columns X (TRUE by default)
component number for the horizontal axis
component number for the vertical axis
: magnification to be used for labels (1 by default)