Re: [R] nested design in lme, need help with specifying model

2007-02-26 Thread Mike Dunbar
Dear Radka I'm not sure I quite understand your design and quite where the nesting comes in. But a quick suggestion is why are you adding species as random as well as fixed? I don't think you can do this or indeed should do it. I think this is why you get problems with your fixed effects. If

[R] nested design in lme, need help with specifying model

2007-02-25 Thread Radka Ptacnikova
Hi, I wonder if anyone can help me with specifying a right model for my analysis. I am a beginner to lme methods and though have spent already many hours studying from various books an on-line helps, I was unfortunately not able to find a solution to my problem on my own. Data structure: I

Re: [R] nested design; intercept

2006-10-04 Thread Mark Difford
Dear R-help, I am sorry if this is more of a stats question than an R-question, but I have found it difficult to get a clear answer by other means. Q. Would it be wrong to specify a nested model and retain a common intercept, e.g. lm(NH4 ~ Site/TideCode + 1) I am aware (?) that my

Re: [R] nested design

2006-06-05 Thread Mark Difford
Jorn, For your model, model-lme(Biomass~Age,random=~1|Age/Stand) think about nesting age in stand (doesn't that makes more sense, anyway ?). If you're lucky the NaN will zip. So, do model - lme( Biomass ~ Age, random = ~ 1 | Stand/Age I've had a similar problem with unbalanced data when

[R] nested design

2006-06-03 Thread Jörn Buse
Hello, there is a problem to calculate the following model: model-aov(Biomass~Beech+Age+Error(Age/Stand)) Warning message: Error() model is singular in: aov(Biomass ~ Beech + Age + Error(Age/Stand)) The summary output is: Error: Age Df Sum Sq Mean Sq Beech 1 142671 142671 Error:

Re: [R] nested design

2006-06-03 Thread Richard M. Heiberger
Your model model - aov(Biomass ~ Beech + Age + Error(Age/Stand)) has a redundancy that might be causing the problem. I can't tell without the data. Try tree.aov - aov(Biomass ~ Beech + Age + Error(Stand %in% Age)) A second potential problem is the class of the variables. From the degrees of

[R] Nested design and GLM: ....continue

2006-05-25 Thread Giovanni Bacaro
Dear list members, First of all thank you for your helpful advices. After your answeres to my firt mail I studied a lot (R-News n°5) and I tried to perform my analysis: First, to fit a GLM with a nested design I decided to use the function lmer in package lme4 as suggested by Spencer Graves and

Re: [R] Nested design

2006-05-21 Thread Spencer Graves
see inline Giovanni Bacaro wrote: Dear list members, I'd like to perform a glm analysis with a hierarchically nested design. In particular, I have one fixed factor (Land Use Classes) with three levels and a random factor (quadrat) nested within Land Use Classes with different levels per

[R] Nested design

2006-05-18 Thread Giovanni Bacaro
Dear list members, I'd like to perform a glm analysis with a hierarchically nested design. In particular, I have one fixed factor (Land Use Classes) with three levels and a random factor (quadrat) nested within Land Use Classes with different levels per classes (class artificial = 1 quadrat;

Re: [R] Nested Design Coding Question

2003-02-19 Thread Douglas Bates
Steeno, Gregory S [EMAIL PROTECTED] writes: I'm a SAS user who is slowly but surely migrating over to R. I'm trying to find the proper code to analyze a nested design. I have four classification variables, L (fixed), A (random within L), D (random within L), and I (random within L). The