CORFAN—FORTRAN IV Computer Program for Correlation, Factor Analysis (R- and Q-Mode) and Varimax Rotation

Abstract

The geological maze (algorithm) as described by Griffiths (1966) illustrates a procedure for problem solving in the geosciences. The researcher collects data, transforms it to normal, classifies, correlates, factors, rotates, separates populations and plots results. Physically, considering the large volumes of data usually involved, it would be difficult to manipulate the analysis with pencil and pad. The digital computer has provided a rapid and precise means of data analysis for the modern researcher. Computer programs have been written separately for correlation, factor analysis and varimax rotation, and are provided at many computer centers.

The objectives of this computer contribution are: (1) to provide the researcher with a multivariate systems program package containing correlation, factor analysis (both R- and Q-modes) and varimax rotation linked together in a single program with a minimum of required parameter cards and computer runs; and (2) to produce a program capable of analyzing large numbers of variables (100) and which to a large extent is machine independent. Computer Contribution 30 (Griffiths and Ondrick, 1968) provided the first stage in statistical data analysis, namely logarithmic transformation, classification and regression analysis of data. The program described here provides a means for accomplishing the second stage in the geological algorithm-multivariate statistical analysis.

Acknowledgments

CORFAN is a composite of four computer programs (COREL, FAN, QMOD, and VROT) originally written in FORTRAN II for the IBM 7074 computer. We express our thanks to The Pennsylvania State University Computation Center staff for the base programs from which this program was constructed. We also wish to thank Prof. John C. Griffiths for reading the manuscript and giving helpful suggestions. The FORTRAN IV program was tested in the GE 635 at the University of Kansas Computation Center.