g03baf
g03baf
© Numerical Algorithms Group, 2002.
Purpose
G03BAF Computes orthogonal rotations for loading matrix, generalized
orthomax criterion
Synopsis
[flr,r,iter,ifail] = g03baf(fl<,stand,g,maxit,acc,ifail>)
Description
Let (Lambda) be the p by k matrix of loadings from a variable-
directed multivariate method, e.g. canonical variate analysis or
factor analysis. This matrix represents the relationship between
the original p variables and the k orthogonal linear combinations
of these variables, the canonical variates or factors. The latter
are only unique up to a rotation in the k-dimensional space they
define. A rotation can then be found that simplifies the
structure of the matrix of loadings, and hence the relationship
between the original and the derived variables. That is the
* *
elements, (lambda) , of the rotated matrix, (Lambda) , are
ij
either relatively large or small. The rotations may be found by
minimizing the criterion:
k p k [ p ]2
-- -- * 4 (gamma) -- [ -- * 2]
V= > > ((lambda) ) - ------- > [ > ((lambda) ) ]
-- -- ij p -- [ -- ij ]
j=1 i=1 j=1[ i=1 ]
where the constant (gamma) gives a family of rotations with
(gamma)=1 giving varimax rotations and (gamma)=0 giving quartimax
rotations.
It is generally advised that factor loadings should be
standardised, so that the sum of squared elements for each row is
one, before computing the rotations.
*
Parameters
g03baf
Required Input Arguments:
fl (:,:) real
Optional Input Arguments: <Default>
stand (1) string 'u'
g real 1
maxit integer 30
acc real 1e-5
ifail integer -1
Output Arguments:
flr (:,:) real
r (:,:) real
iter integer
ifail integer