Aloha all, I have a data frame with 4 columns. The first three are factors (f1, f2, f3) and the fourth is numeric. I'd like to explore these data using median polish. To do that I plan to use medpolish() on the matrix[f1,f2xf3], then medpolish on the resulting matrix[f2,f3]. This approach is described by Cook on page 141 of Exploring Data Tables, Trends, and Shapes.
split() gets me close to where I want to be, but results in a list, rather than a matrix. How do I construct the matrix[f1,f2xf3] from my data frame? Also, any pointers to existing code that performs multi-way median polish will be appreciated. Sorry for the newbie-type query, but manipulating data prior to analysis is really hard for me in R. All the best, Tom Thomas S. Dye, Ph.D. T. S. Dye & Colleagues, Archaeologists, Inc. Phone: (808) 529-0866 Fax: (808) 529-0884 http://www.tsdye.com [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.