Re: [R] Help with lmer formula

2012-07-03 Thread Camila Mendes
Thanks Joshua for the clear explanation. I've previously posted in r sig mixed, but I got no response... :( Cheers, - Camila On Mon, Jul 2, 2012 at 9:31 PM, Joshua Wiley jwiley.ps...@gmail.com wrote: Hi Camila, In mixed equation form instead of multilevel, it would be: Y_it = gamma_00 +

[R] Help with lmer formula

2012-07-02 Thread Camila Mendes
Hey all - I am a newbie on mixed-effects models. I want to estimate the following model: Y_it = alpha_0t + alpha_1t*X_it + e_it alpha_0t = gamma_00 + u_0t alpha_1t = gamma_10 + gamma_11*W_it + u_1j Where Y is my outcome, X is my level-1 predictor, and W is my level 2 predictor. I am not sure

Re: [R] Help with lmer formula

2012-07-02 Thread Bert Gunter
Wrong list. Post to r-sig-mixed-models. -- Bert On Mon, Jul 2, 2012 at 6:47 PM, Camila Mendes cacamende...@gmail.comwrote: Hey all - I am a newbie on mixed-effects models. I want to estimate the following model: Y_it = alpha_0t + alpha_1t*X_it + e_it alpha_0t = gamma_00 + u_0t alpha_1t

Re: [R] Help with lmer formula

2012-07-02 Thread Joshua Wiley
Hi Camila, In mixed equation form instead of multilevel, it would be: Y_it = gamma_00 + gamma_10*X_it + gamma_11*W_it*X + (e_it + u_0t + u_1j*X) your code seems reasonable. Note that the random intercept and slope will be correlated in your specification (unstructured if you want, it is

Re: [R] Help with lmer

2011-06-26 Thread Sophie Higgins
-project.org CC: england...@hotmail.com Subject: Re: [R] Help with lmer Date: Fri, 24 Jun 2011 17:19:00 +0200 Sophie, I'm myself quite new to linear mixed effect models, but PresenceAbsence sounds like a binary response variable. So wouldn't be m1-lmer(Presencebsence~Habitatype*Width

Re: [R] Help with lmer

2011-06-26 Thread Hugo Mildenberger
: hugo.mildenber...@web.de To: r-help@r-project.org CC: england...@hotmail.com Subject: Re: [R] Help with lmer Date: Fri, 24 Jun 2011 17:19:00 +0200 Sophie, I'm myself quite new to linear mixed effect models, but PresenceAbsence sounds like a binary response variable. So

[R] Help with lmer

2011-06-24 Thread Sophie Higgins
Hey, I am having trouble with lmer. I am looking at the presence/absence of water shrews against habitat and other factors e.g so I used this: m1-lmer(Presencebsence~Habitatype*Width+(1|Sitename))summary(m1) But i keep getting this error up Error in mer_finalize(ans) : Downdated X'X is not

Re: [R] Help with lmer

2011-06-24 Thread Hugo Mildenberger
Sophie, I'm myself quite new to linear mixed effect models, but PresenceAbsence sounds like a binary response variable. So wouldn't be m1-lmer(Presencebsence~Habitatype*Width+(1|Sitename),familiy=binomial) the first thing to try? There is also a special mailing list for linear - mixed

[R] Help with lmer, nested data and repeated measures

2010-11-18 Thread Simon Garnier
Dear all, I'm discovering the somehow confusing (for me) world of linear mixed models after having been advised it could be the best option to analyze my dataset. After several days of reading, I'm not sure that what I ended up with makes some sense and I'd greatly appreciate any help and

Re: [R] Help with lmer, nested data and repeated measures

2010-11-18 Thread Bert Gunter
You would be better off posting to R-sig-mixed-models or R-sig-ecology -- Bert On Thu, Nov 18, 2010 at 9:58 AM, Simon Garnier sgarn...@princeton.edu wrote: Dear all, I'm discovering the somehow confusing (for me) world of linear mixed models after having been advised it could be the best