# GPA Rotation for Factor Analysis

### Description

GPArotation implements Gradient Projection Algorithms and several rotation objective functions for factor analysis.

### Details

Package: | GPArotation |

Depends: | R (>= 2.0.0) |

License: | GPL Version 2. |

URL: | http://www.stat.ucla.edu/research or |

http://www.stat.ucla.edu/research/gpa |

The main optimization functions are
`GPForth`

and `GPFoblq`

. Rotation objectives include
`oblimin`

and many others.

### Author(s)

Coen A. Bernaards and Robert I. Jennrich with some R modifications by Paul Gilbert.

Code is modified from original source ‘splusfunctions.net’ available at http://www.stat.ucla.edu/research/gpa.

### References

The software reference is

Bernaards, C.A. and Jennrich, R.I. (2005) Gradient Projection Algorithms
and Software for Arbitrary Rotation Criteria in Factor Analysis.
*Educational and Psychological Measurement*, **65**, 676–696.

Theory of gradient projection algorithms may be found in:

Jennrich, R.I. (2001). A simple general procedure for orthogonal rotation.
*Psychometrika*, **66**, 289–306.

Jennrich, R.I. (2002). A simple general method for oblique rotation.
*Psychometrika*, **67**, 7–19.

### See Also

`rotations`

,
`GPForth`

,
`GPFoblq`

,
`factanal`