[R-pkgs] GPArotation package

[Paul Gilbert]

We have just put a package GPArotation on CRAN. The functions in this 
package perform an number of different orthogonal and oblique rotations 
for factor analysis, using the gradient projection algorithm described 
in Coen A. Bernaards and Robert I. Jennrich  (2005),  "Gradient 
Projection Algorithms and Software for Arbitrary Rotation Criteria in 
Factor Analysis, ", Educational and Psychological Measurement (in 
press).  Additional details are available on the web site  
<http://www.stat.ucla.edu/research/gpa>.

The following rotations are available:

oblimin     oblique       oblimin family       
quartimin   oblique                    
targetT     orthogonal    target rotation       
targetQ     oblique       target rotation       
pstT         orthogonal    partially specified target rotation
pstQ         oblique       partially specified target rotation
oblimax     oblique                    
entropy     orthogonal    minimum entropy       
quartimax   orthogonal                 
varimax     orthogonal                 
simplimax   oblique                    
bentlerT    orthogonal    Bentler's invariant pattern simplicity criterion
bentlerQ    oblique       Bentler's invariant pattern simplicity criterion
tandemI     orthogonal    Tandem Criterion         
tandemII    orthogonal    Tandem Criterion         
geominT     orthogonal                   
geominQ     oblique                      
cfT         orthogonal    Crawford-Ferguson family     
cfQ         oblique       Crawford-Ferguson family     
infomaxT    orthogonal                   
infomaxQ    oblique                      
mccammon    orthogonal    McCammon minimum entropy ratio

Other rotations can be fairly easily added simply by coding a small 
function to calculate the rotation criterion objective function, and 
its gradient. A detailed example of gradient computation is in the
paper mentioned above.

Paul Gilbert and
Coen Bernaards