Chuck Cleland <[EMAIL PROTECTED]> writes: > A. Bolu Ajiboye wrote: > > Can R do a repeated measures MANOVA and tell what dimensionality the > > statistical variance occupies? > > > > I have been using MATLAB and SPSS to do my statistics. MATLAB can do > > ANOVAs and MANOVAs. When it performs a MANOVA, it returns a > > parameter d that estimates the dimensionality in which the means lie. It > > also returns a vector of p-values, where each p_n tests > > the null hypothesis that the mean vectors lie in an n-1 dimensional space > > (0-D space implies same vector, 1-D space implies scaled > > vectors that point in the same direction, etc...). However, MATLAB does > > not do repeated measures MANOVA. SPSS can do repeated > > measures MANOVA but it does not return this dimension output. Hence, I'm > > trying to find an environment that will allow me to do > > repeated measures MANOVA and determine the dimensionality of the space, > > before I spend several weeks trying to learn it. > > > > I know the dimensionality parameter is based upon the eigenvalues of the > > ratio of the different SSCP (sum of squares and cross > > products) matrices, but a) I'm not sure how to calculate the SSCP matrices > > for repeated measures MANOVA, and b) once I get these > > eigenvalues and convert them a Pillai-Bartlett or Wilk's-Lambda value, I > > dont know how to convert to an f-statistic. > > > > Does anybody know how to do this or has repeated measures MANOVA in R > > (while returning the dimensionality parameter)? Thanks in > > advance for your help. > > I don't know about the dimensionality parameter, but have a look at > anova.mlm(). In particular, you might want to run example(anova.mlm) > and study the output. Also, you might look at SSD() and > summary.manova() in package stats.
Yep. You may also want to look at http://www.pubhealth.ku.dk/bs/publikationer/rr-06-11.pdf/ (which is under revision for R News) Re. dimensionality, it is not clear to me what exactly Matlab might be doing and how (and I can't easily find it on the net, or so it seems). -- O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ [email protected] 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.
