similar to: Post hoc Multiple comparison

Displaying 20 results from an estimated 2000 matches similar to: "Post hoc Multiple comparison"

2003 May 14
1
Multiple comparison and lme (again, sorry)
Dear list, As a reply to my recent mail: > simint and TukeyHSD work for aov objects. > Can someone point me to similar functions for lme objects? Douglas Bates wrote There aren't multiple comparison methods for lme objects because it is not clear how to do multiple comparisons for these. I don't think the theory of multiple comparisons extends easily to lme models. One could
2003 Apr 03
2
Matrix eigenvectors in R and MatLab
Dear R-listers Is there anyone who knows why I get different eigenvectors when I run MatLab and R? I run both programs in Windows Me. Can I make R to produce the same vectors as MatLab? #R Matrix PA9900<-c(11/24 ,10/53 ,0/1 ,0/1 ,29/43 ,1/24 ,27/53 ,0/1 ,0/1 ,13/43 ,14/24 ,178/53 ,146/244 ,17/23 ,15/43 ,2/24 ,4/53 ,0/1 ,2/23 ,2/43 ,4/24 ,58/53 ,26/244 ,0/1 ,5/43) #R-syntax
2003 May 19
1
Syntax for random effect in glmmPQL
Dear R-listers I wonder if someone can help me with the syntax for the random effect in glmmPQL()? I have a data set with a response variable "y" (counts), two dependent variables: "treat" (4 levels) and "site" (2 levels). The latter, I want to use as a random variable. How do I specify this in the function? Is it like this:
2007 Oct 30
2
calculate spatial distance
Hi, I have a set of locations defined by longitude and latitude (in degrees), and want to calculate the spatial (or geographic) distance among all locations. I did not find such a function in the spatial-related packages. (I *cannot* use 'dist', as I have geographic, not cartesian coordinates). thanks! Robert Robert Ptacnik Norwegian Institute for Water Research (NIVA) Gaustadall?en 21
2005 Mar 09
1
multiple comparisons for lme using multcomp
Dear R-help list, I would like to perform multiple comparisons for lme. Can you report to me if my way to is correct or not? Please, note that I am not nor a statistician nor a mathematician, so, some understandings are sometimes quite hard for me. According to the previous helps on the topic in R-help list May 2003 (please, see Torsten Hothorn advices) and books such as Venables &
2008 Jul 04
1
kriging problem(?)
Hei, I have two spatial datasets Sa and Sb, both with lat-lon coordinates and from same geographic area, but from different localities within the area (independent samples). Sa is biotoc data, Sb is some environmental parameter (fertility). I 'know' that Sb affects Sa, but wonder on which scale. I tried different interpolations by creating different grids of Sb (e.g. 20x20 and 100x100
2009 Dec 04
2
csimtest function in multcomp package
Hello all, Quick question: I want to do posthoc contrasts for a linear mixed effects model. However, when trying to use the csimtest function in multcomp package I receive an error message saying it cannot find the function, even after installing and loading package multcomp. Any pointers would be greatly appreciated Daniel
2003 May 19
1
multcomp and glm
I have run the following logistic regression model: options(contrasts=c("contr.treatment", "contr.poly")) m <- glm(wolf.cross ~ null.cross + feature, family = "binomial") where: wolf.cross = likelihood of wolves crossing a linear feature null.cross = proportion of random paths that crossed a linear feature feature = CATEGORY of linear feature with 5 levels:
2007 Nov 28
2
fit linear regression with multiple predictor and constrained intercept
Hi group, I have this type of data x(predictor), y(response), factor (grouping x into many groups, with 6-20 obs/group) I want to fit a linear regression with one common intercept. 'factor' should only modify the slopes, not the intercept. The intercept is expected to be >0. If I use y~ x + factor, I get a different intercept for each factor level, but one slope only if I use y~ x *
2007 Feb 07
1
heteroscedasticity problem
Dear Listers, I have a regression problem (x->y) with biological data, where x influences y in two ways, (1) y increases with x and (2) the variation around the mean (residuals) decreases with increasing x, i.e. y becomes more 'predictable' as x increases. The relationship is saturating, y~a + bx + cx^2, gives a very good fit. I know basically how to test for heteroscedasticity. My
2007 Nov 29
1
relative importance of predictors
Hei Group, I want to compare the relative importance of predictors in a multiple linear regression y~a+bx1+cx2... However, bptest indicates heteroskedasticity of my model. I therefore perform a robust regression (rlm), in combination with bootstrapping (as outlined in J. Fox, Bootstrapping Regression Models). Now I want to compare the relative importance of my predictors. Can I rely on the
2006 Feb 07
1
post-hoc comparisons following glmm
Dear R community, I performed a generalized linear mixed model using glmmPQL (MASS library) to analyse my data i.e : y is the response with a poisson distribution, t and Trait are the independent variables which are continuous and categorical (3 categories C, M and F) respectively, ind is the random variable. mydata<-glmmPQL(y~t+Trait,random=~1|ind,family=poisson,data=tab) Do you think it
2004 Feb 20
1
nlme and multiple comparisons
This is only partly a question about R, as I am not quite sure about the underlying statistical theory either. I have fitted a non-linear mixed-effects model with nlme. In the fixed part of the model I have a factor with three levels as explanatory variable. I would like to use Tukey HSD or a similar test to test for differences between these three levels. I have two grouping factors:
2005 Oct 14
1
smbcacls add acl fails 3.0.20
Hi all! I have a problem setting ACLs on a remote file on a Windows XP Pro SP2 box. I issue the following command: smbcacls -a 'ACL:BBI-DEV\beakid:ALLOWED/0/0x00100116' -U 'BBI-DEV \Admin' //BBI-DEV/Data /Niva.txt And I get this response from debug level 3. Password: Connecting to host=BBI-DEV Connecting to 192.168.1.124 at port 445 Doing spnego session setup (blob
2003 Oct 08
2
binomial glm warnings revisited
Dear all, Last autumn there was some discussion on the list of the warning Warning message: fitted probabilities numerically 0 or 1 occurred in: (if (is.empty.model(mt)) glm.fit.null else glm.fit)(x = X, y = Y, when fitting binomial GLMs with many 0 and few 1. Parts of replies: "You should be able to tell which coefficients are infinite -- the coefficients and their standard errors will
2005 Oct 17
1
smbcacls add fails 3.0.20a
Hi all! I have a problem setting ACLs on a remote file on a Windows XP Pro SP2 box. I issue the following command: smbcacls -a 'ACL:BBI-DEV\beakid:ALLOWED/0/0x00100116' -U 'BBI-DEV \Admin' //BBI-DEV/Data /Niva.txt And I get this response from debug level 3. Password: Connecting to host=BBI-DEV Connecting to 192.168.1.124 at port 445 Doing spnego session setup (blob
2005 May 23
0
using lme in csimtest
Hi group, I'm trying to do a Tukey test to compare the means of a factor ("treatment") with three levels in an lme model that also contains the factors "site" and "time": model = response ~ treatment * (site + time) When I enter this model in csimtest, it takes all but the main factor "treatment" as covariables, not as factors (see below). Is it
2002 Jul 01
1
How to do multiple comparisons with multiple error strata
Hello, the title says it all. I have an ANOVA model with "Error" term and the functions TukeyHSD or those from the "multcomp" package seem not to work with such a model. Assuming that the object returned from aov() function with multiple strata is a list of aov objects, I tried something like TukeyHSD(aov.1$Within), but this does not work either. Does somebody have a
2003 May 05
1
multcomp and lme
I suppose that multcomp in R and multicomp in S-Plus are related and it appears that it is possible to use multicomp with lme in S-Plus given the following correspondence on s-news sally.rodriguez at philips.com 12:57 p.m. 24/04/03 -0400 7 [S] LME summary and multicomp.default() Is it possible to use multicomp with lme in R and if so what is the syntax from a simple readily available
2007 May 21
2
more simplified output from glht object
Hi, I use glht to make multcomp, using Tukey, from a glm model. It is possible to get a more simplified output of result? Somethink like ordering by letters. Thanks Ronaldo -- Human kind cannot bear very much reality. -- T. S. Eliot, "Four Quartets: Burnt Norton" -- > Prof. Ronaldo Reis J?nior | .''`. UNIMONTES/Depto. Biologia Geral/Lab. de Ecologia | : :' :