similar to: Sphericity test

Hi R-users I'm working with a data.frame of 40000 x 10, for which I need to apply the "split" function. The result is very long and cannot be stored in a variable due to memory exceeding. I've tried to send the result directly to a file through sink(filename) function, but the problem still occurs. Does anyone have an idea to solve this issue? > dim(dados) [1] 40000 10

Dear R helpers I have a daily rainfall dataset of 5 stations, but the time-series are of different lengths. Three stations measured precipitation from 1917 to 2004, one from 1930 to 1979, and other from 1975 to 1998. I'd like to know how to analyse if rainfall is similiar at all stations. Is it possible to compare time-series like these? Best Regards!

Hi R-users I'd like to know if there is some packages or functions to do comparison of treatments after that manova pointed differences between them. Any suggestions are much appreciated. __________________________________________________________ Eng. Agr., M.Sc. Eduardo Dutra de Armas __________________________________________________________ Centro de Energia Nuclear na Agricultura

Hi R-users Does anyone know how to increase the resolution of plots to be exported? I'm exporting some plots but the maximum resolution that I get is 96 dpi. I want to get files with 300dpi. Thanks! __________________________________________________________ Eng. Agr., M.Sc. Eduardo Dutra de Armas __________________________________________________________ Centro de Energia Nuclear na

Hi R-users I recently downloaded RdbiPgSQL 1.8.0 and Rdbi 1.8.0 from Bioconductor to be installed under R 2.4.1. When requiring RdbiPgSQL an error message is showed as follows: > require(RdbiPgSQL) Loading required package: RdbiPgSQL Error in library(package, lib.loc = lib.loc, character.only = TRUE, logical = TRUE, : ‘RdbiPgSQL’ is not a valid package – installed <

I have 3 questions (below). Background: I am teaching an introductory statistics course in which we are covering (among other things) repeated measures anova. This time around teaching it, we are using R for all of our computations. We are starting by covering the univariate approach to repeated measures anova. Doing a basic repeated measures anova (univariate approach) using aov() seems

Hi R-users I'm trying to do multivariate analysis of variance of a experiment with 3 treatments, 2 variables and 5 replicates. The procedure adopted in SAS is as follow, but I'm having difficulty in to implement the contrasts for comparison of all treatments in R. I have already read manuals and other materials about manova in R, but nothing about specific contrasts were found in them,

Is there a function that calculates the power of a repeated-measure ANOVA design, e.g., 2 groups, 4 within-subject factors, an average 0.40 correlation between the 4 within factors, etc. I don't think I can use power.anova.test() because it does not consider corr=0.40. I am hoping that someone has already implemented the method by Muller & Barton (1989, JASA 84: 549-555) on how to

Dear Prof. Baron, thankyou for your pdf paper on using R, at http://www.psych.upenn.edu/~baron/rpsych.pdf I am currently interested in the sphericity notes on pp. 45-47. The equation on p. 46 suggests the following R calculation: D <- k^2 * ( mean(diag(S)) - mean(S) )^2 while the notes in the pdf indicate the following: D <- k^2 * ( mean(S) - mean(diag(S)) )^2 Can you please consider

I haven't been able to find an answer on this that's direct, only implied. In several places I have read that when people asked for sphericity tests they were guided toward lme or mlm models. But, there is no direct indication that the lme method is not subject to the sphericity assumption. In fact, it seems like it should be. Its just a linear model that handles random and

Hey, Is this right for a sphericity test? x <- mymatrix mycov <- cov(x) bartlett.text (array (mycov), myconditions)

Hi, I'm getting to grips with using R to perform repeat measures analysis of variance and was wondering is there a potted method to obtain Huynh and Feldt or other adjustments for sphericity violations? Thanks Dominic Dr Dominic J Barraclough Dept Neurobiology and Anatomy, University of Rochester, 601 Elmwood Av, Box 603, Rochester NY 14642 tel (716) 2753627 dominic_barraclough at

I believe that the following function is a good function for eyeballing sphericity. But, I can't find functions for tests anywhere (g-g or h-f). Anyone who wants to can feel free to use it. It is bad that R does not provide any tests for sphericity AND cannot do a MANOVA on repeated measures (although lme is an alternative add on package). One of these solutions must be provided in the

Does anyone have any suggestions for how to test for violation of the sphericity assumption and apply the Huynh-Feldt correction to a repeated-measure model? My model follows the format below: Rep.anova=aov(Y~X1*X2+Error(Subject/(X1*X2),data=DataFile)) I've already looked at the explanations aov() and Error() in Baron's “Notes on the use of R for psychology experiments and

Hi, Is there a way to do a sphericity test in R for repeated measures ANOVA (using aov or lme)? I can't find anything about it in the help. Thanks Orou [[alternative HTML version deleted]]

Hello and thanks in advance I am running a glm in R the code is as follows with residual diagnostic code below model4<-glm(Biomass~(Treatment+Time+Site)^2, data=bobB, family=quasi(link="log", variance="mu")) par(mfrow=c(2,2)) plot(model2) to test the effect of grazing exclusion of feral horses for a Phd with following factors: Treatment - 3 levels which are grazed

With respect to calculating the epsilon index of sphericity for ANOVA, discussed on pp. 45-47 of: http://www.psych.upenn.edu/~baron/rpsych.pdf It notes that epsilon is not required for a repeated measures design with only k=2 levels, as the minimum value of epsilon (e) is given by: e = 1/(k-1) so for k=2, we have e = 1 (ie, no correction of the F test df; see p. 46). These notes apply to a

Hello everyone, I am trying to do within subjects repeated measures anova followed by the test of sphericity (sample dataset below). I am able to get either mixed model or linear model anova and TukeyHSD, but have no luck with Repeated-Measures Assuming Sphericity or Separate Sphericity Tests. I am trying to follow example from "car" package, but it seems that I am not getting something

Apologies for the obvious, but just to clarify: there is no reason to "justify" a PCA -- it's just an eigen decomposition of a matrix and is therefore "justified" by linear algebra. If one wants to determine whether some subset of the eigenvectors = principal components suffice to "represent" the data in some sense, then that is where distributional

I'm an experimental psychologist and when I run ANOVA analysis in SPSS, I normally ask for a test of non-sphericity (Box's M-test). I also ask for output of the corrections for non-sphericity, such as Greenhouse-Geisser and Huhn-Feldt. These tests and correction factors are commonly used in the journals for experimental and other psychology reports. I have been switching from SPSS to R