parameter which determines the type of rotation performed.
Common rotations and the corresponding value of gamma are:
varimax (1), quartimax (0), and equamax (k/2).
Generally positive values (not larger than about 5*k) are used for gamma,
but negative values are possible.
normalize:
logical flag: if TRUE,
Kaiser normalization is performed. In Kaiser normalization
(Kaiser, 1958), the criterion is adjusted so that the rows
in amat are adjusted to an L-2 norm of 1.
iter.max:
the maximum number of iterations allowed.
eps:
when the change in the orthomax criterion is less than eps from one iteration
to the next, convergence is assumed.
VALUE:
a list with the following components:
rmat:
the rotated version of amat.
gamma:
the value of gamma used.
normalize:
the input value of normalize.
iterations:
the number of iterations used.
tmat:
the transformation matrix.
Thus amat %*% tmat is equal to rmat up to numerical precision.
orthogonal:
the value TRUE.
DETAILS:
This computes rotations for the orthomax family of rotations by
performing rotations on pairs of columns.
The criterion that is being minimized is:
sum(lam^2) - gamma/p * sum(apply(lam, 1, sum)^2)
where lam is the (possibly) normalized version of the rmat output
with all elements squared.
REFERENCES:
Harman, H. H. (1976).
Modern Factor Analysis,
3rd Edition.
University of Chicago Press, Chicago.
Kaiser, H. F. (1958). The varimax criterion for analytic rotation in
factor analysis.
Psychometrika
23 187-200.