Biplots for Principal Components and Factor Analysis Models

DESCRIPTION:

Produces a biplot corresponding to the model.

USAGE:

biplot.princomp(x, choices=1:2, scale=1, ...) 
biplot.factanal(x, choices=1:2, scale=1, ...) 

REQUIRED ARGUMENTS:

x
an object of class "princomp" or "factanal".

OPTIONAL ARGUMENTS:

choices
length 2 vector stating which components or factors to plot.
scale
a number between 0 and 1, inclusive that tells what kind of scaling to perform. The basic scaling factors, lambda, are the singular values of the data in the case of principal components and the square root of the sum of squared loadings in the case of factor analysis. The variables are scaled by lambda ^ scale and the observations are scaled by lambda ^ (1-scale). See Gabriel (1971).
...
optional arguments to biplot.default may be given.

SIDE EFFECTS:

a plot is produced on the current graphics device.

DETAILS:

These are methods for the generic function biplot.

REFERENCES:

Gabriel, K. R. (1971). The biplot graphical display of matrices with applications to principal component analysis. Biometrika 58 453-467.

SEE ALSO:

, , .

EXAMPLES:

prim4.pcr <- princomp(prim4, covlist=cov.mve(prim4), cor=T) 
biplot(prim4.pcr) 
biplot(prim4.pcr, 2:3)