similar to: Brown-Forsythe F* Statistic

Dear friends, two years ago (as I found on the web) Paul sent the following message but I was not able to find if he got an answer. Today I have the same question and it would be great if I could find out that this test has been implemented (somehow) in R. Please do not confuse it with the Brown-Forsythe test of equality of variances. Thank you: I've been searching around for a function for

Does oneway.test do what you want? Hope this helps, Matt Wiener -----Original Message----- From: r-help-bounces at stat.math.ethz.ch [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Sven Hartenstein Sent: Monday, June 21, 2004 3:23 PM To: r-help at stat.math.ethz.ch Subject: [R] Welch-JM-Test or Brown-Forsythe-Test in R? Hi, I want to test mean differences of > 2 groups with

Hi, do anyone know which statistical software have the Brown-Forsythe Test for differences of numerical continue data groups wich variance heterogenity? not ofr evaluate the homogenity of variances, for evaluated the differences between groups as ANOVA. thanks Jos?? Herrera M??xico _________________________________________________________________ T1msn Search. Todo lo que buscas ahora m??s

I have heterogeneous variance in a two-way mixed effects ANOVA, with more than 2 groups in each factor. Is there something like oneway.test or a Brown-Forsythe test that will let me test for differences in means? Thanks! -Keith

Suppose you have a vector of data in x and response values in y. How do you plot together both the points (x,y) and the curve that results from the fitted model, if the model is not y ~ x, but a higher order polynomial, e.g. y~poly(x,2)? (In other words, abline doesn't work for this case.) Thanks, --Paul -- Paul Lynch Aquilent, Inc. National Library of Medicine (Contractor)

Hi, I'm just starting out on R. I have an example data frame listed below. I have regressed Y on X1. lm(Y~X1). Would like to obtain the Brown-Forsythe test on residuals. I am unsure of how to conduct the following steps. (1) Inputting the residuals from regression into the data frame. (2) Splitting the groups above (X11) and below mean of X1 (X12) in the data frame. (3) Calculating the sum

Is there a download page for mongrel_cluster? I see that "gem install mongrel_cluster" works, but I can''t see where it''s coming from. Usually gems have some sort of project page somewhere. -- Paul Lynch Aquilent, Inc. National Library of Medicine (Contractor)

Hi, i'm looking for an R function to fit a one-way ANOVA with one factor containing 10 levels. The factor levels have different numbers of observations (varying between 20 to 40). For most of the dependent variables i'm testing there are unequal variances among the factor levels. I see the function oneway.test: oneway.test(variable ~ factor, data=dataset) which by default does not

Dear R users I get different F-statistic results for a "within" model, when using "time" or "twoways" effects in plm() [1] and when manually specifying the time control dummies [2]. [1] vignette("plm") [2] http://cran.r-project.org/doc/contrib/Farnsworth-EconometricsInR.pdf Two examples below: library("AER") data("Grunfeld", package =

Hi, I'm trying to do a linear regression style one-way ANOVA using some data in a data frame, and (perhaps because I am still relatively unfamiliar with both R and statistics) what I thought I should do was to make the data frame into a factor. By that I mean that I have a data frame whose column labels are the levels of the factor, and the values in the frame are numeric values for the

I would appreciate confirmation that the function vcov(model.nlme) gives the var-cov matrix of the fixed effects in an nlme model. Presumably the random-effects var-cov matrix is given by cov(ranef (model.nlme)? Rob Forsyth

In some trial simulation work I need to create batch files that will repeatedly generate pseudoreplicate datasets and then create non- linear mixed effects models using nlme. Inevitably these models sometimes fail to converge but I need the batch file to simply move on to another simulation rather than abort. I am using the try() function as in model<-try((nlme(...))) which handles

This morning I tried to see if I could find the r-help mailing list on Google Groups, which has an interface that I like. I found three Google Groups ("The R Project for Statistical Computing", "rproject", and "rhelp") but none of them are connected to the r-help list. Is there perhaps some reason why it wouldn't be a good thing for there to be a connected

Hello everybody, I use the sweetpotato database included in R package: data(sweetpotato) This dataset contains two variables: yield(continous variable) and virus(factor variable). Due to Levene test is significant I cannot assume homogeneity of variances and I apply Welch test in R instead of one-way ANOVA followed by Tukey posthoc. Nevertheless, the problems come from when I apply posthoc

Dear all a couple of months ago i've found threads regard test that verify AnOVa assumption on homogeneity of variances. Prof. Ripley advice LDA / QDA procedures, many books (and many proprietary programs) advice Hartley's F_max, Cochran's minimum/maximum variance ratio (only balanced experiments), K^2 Bartlett's test, Levene's test. Morton B. Brown and Alan B. Forsythe in a

Is there an option for filtering stop words out of the query string, so that queries that contain stop words don''t return zero results? It has been several years, but I think that when I was on a project that was writing a search engine, we used to filter stop words both out of the index and out of the query string, after it was parsed. This allows a query like [cold and sinus] to

I've made some normal plots of my data using qqplot, and now I would like to fit a line to the points on the plot and check the correlation coefficient to have a more objective measure of how straight the line is. Is there a simple way of doing that? (I'm still pretty new to R.) Thanks, --Paul -- Paul Lynch Aquilent, Inc. National Library of Medicine (Contractor)

Hello everyone: I'm a new member of this group. I have a question about "oneway.test". When I use "anova(lm(....))" to analysis the ANOVA, I can get the information about Sum Sq and Mean Sq. (The R code and the results are as follows.)

The Brown-Forsyth test for homogeneity of variance is included in the HH package, downloadable from CRAN. library(HH) x <- c(rnorm(1000), rnorm(1000, 0, 1.2)) tmp <- data.frame(x=x, group=rep(c("s1","s1.2"), c(1000,1000))) plot.hov(x ~ group, data=tmp) hov(x ~ group, data=tmp)

After loading the RODBC package version 1.1-7, Ctrl-C changes its behaviour and is quitting R and returning to the (unix-)command prompt on the solaris2.8 platform here. Here's what happened before and after loading RODBC > for (i in 1:10^5) rnorm(10) ^C > library(RODBC) > for (i in 1:10^5) rnorm(10) ^C bash-3.00$ platform sparc-sun-solaris2.8 arch