search for: multimodel

I'm using Rspec and FactoryGirl to create specs for multimodel paperclip attachments. From searching other questions, it seems like a single image attachment is more common. Car.rb class Car < ActiveRecord::Base has_many :uploads, dependent: :destroy validates :uploads, presence: { message: 'You must upload at least one image' }...

Hi everyone, I'm new to this list and have searched R help prior for an answer to this question, without luck. If I'm posting in error, please forgive. I'm thinking about using package MuMIn to do multimodel inference with logistic regression. I have many (25) possible predictors and am curious if there is a way to estimate how long the dredge command might take to run? Any suggestions most welcome. Thanks, erika [[alternative HTML version deleted]]

Hello, I'm running a multimodel analysis which involves fitting several GAM models as implemented in package mgcv. The issue I'm having is that when I try to fit my model, gam gives me the following error message: 'Error in initial.sp(w * X, S, off) : S[[2]] matrix is not +ve definite.' The strange part of this is th...

In a generalized linear model with k covariates, there are 2(kth power) - 1 possible models (excluding interactions). Awhile ago a posting to R-help suggested Model Selection and Multimodel Inference, 2nd ed, by Burnham and Anderson as a good source for understanding model selection. They recommend (page 71) computing AIC differences over all candidate models in the set of possible models. After looking at the help page for stepAIC and checking MASS, I am not certain which AICs are e...

Hello I am not able to use the MuMIn package (version 1.7.7) for multimodel inference with a GLM Negative Binomial model (It does work when I use GLM Poisson). The GLM Negative Binomial gives the following error statement: Error in get.models(NBModel, subset = delta < 4) : object has no 'calls' attribute Here is the unsuccessful Negative Binomial code. >...

...tion 2. The reason I'm following a manual specification of models relates to the fact that in reality I am using mgcv::gam, and I'm not aware that dredge is able to separate individual smooth terms out of say s(a,b). Hence an additional request, if anyone has example code for using gam in a multimodel inference framework, especially with bivariate smooths, I'd be most grateful. Cheers and Thanks in Advance Mike require(MuMIn) data(Cement) # option 1, create model.selection object using dredge fm0 <- lm(y ~ ., data = Cement) print(dd <- dredge(fm0)) fm1 <- lm(formula = y ~ X1 + X2,...

First of all, I have GAMs noxd<-gam(newNOX~pressure+maxtemp+s(avetemp,bs="cr")+s(mintemp,bs="cr")+s(RH,bs="cr")+s(solar,bs="cr")+s(windspeed,bs="cr")+s(transport,bs="cr"),family=gaussian (link=log),groupD,methods=REML) Then I type " summary(noxd)". and show Family: gaussian Link function: log Formula: newNO2 ~ pressure

...=propspec) pss<-standardize(ps,standardize.y = FALSE) psdrg<-dredge(pss) summary(model.avg(get.models(psdrg,subset=delta<2))) #-------------------------------------------------------------------------------------# REf -Grueber, C.E., Nakagawa, S., Laws, R.J. & Jamieson, I.G. (2011) Multimodel inference in ecology and evolution: challenges and solutions. Journal of evolutionary biology, 24, 699-711. Any help would be much appreciated Regards Andrew Robertson PhD student Centre for Ecology and Conservation University of Exeter, Cornwall Campus Tremough, Cornwall. TR10 9EZ UK Tel: 01326...

Hello R users I'm using MuMIn but for some reason I'm not getting the adjusted confidence interval and uncoditional SE whe I use model.avg(). I took into consideration the steps provided by Grueber et al (2011) Multimodel inference in ecology and evolution: challenges and solutions in JEB. I created a global model to see if malaria prevalence (binomial distribution) is related to any life history traits of 14 different birds species, while controling for Family and genus in a GLMM: global.model.Para<-lmer(cbind...

Subject: Eliminate repeated components from a vector X-Mailer: VM 7.00 under 21.4 (patch 6) "Common Lisp" XEmacs Lucid Reply-To: fjmolina at lbl.gov FCC: /home/f/.xemacs/mail/sent Does anyone know how I can eliminate repeated elements from a vector?

Dear list, I am currently working with a rather large data set on body temperature regulation in wintering birds. My original model contains quite a few dependent variables, but I do not (of course) wish to keep them all in my final model. I've fitted the following model to the data: >

...c weights } \item{models}{the list of models} } \references{ Anderson, D.R., Link, W.A., Johnson, D.H. and Burnham, K.P. (2001). Suggestions for presenting the results of data analyses. Journal of Wildlife Management, 65, 373-378; Burnham, K.P. and Anderson, D.R. (2002) Model Selection and Multimodel Inference: a Practical Information-Theoretic Approach, 2nd edn., Springer-Verlag, New York. 353 pp } \author{ Patrick Giraudoux and David Pleydell: pgiraudo at univ-fcomte.fr, dpleydel at univ-fcomte.fr } \seealso{ \code{\link{AIC}},\code{\link{logLik}} } \examples{ library(MASS) anorex.1 &lt...

...uot;. Unfortunately I could not find any further ellaboration of this corollary anywhere in the book, but maybe I didn't look hard enough. Additionally, you may want to work with "evidence ratios" and Akaike weights, as recommended in Burnham and Anderson, "Model Selection and Multimodel Inference", 2002, Springer. I am under the impression that to try to interpret the AIC in terms of sampling-distribution inference theory, such as in signficance tests, is to miss the point. Ruben

hello, could somebody refer me to the reason R uses -2*loglik + 2*(#param)+2 to calculate AIC? thank you -- Stoyan Iliev

Dear moderator, If possible I would like to send in the following question for R-help: I am analyzing a small data set using PGLS with phylogenetic uncertainty taken into account and thereby including 100 potential phylogenetic tree scenarios. I've managed to run models on all of the different trees and performed model averaging to get parameter estimates for the intercept and most of the

...gh_association.rb (insert_record). Now I may trap this exception in controller and do something with it, however I lose in some way my validation error messages on my form, which is dynamic (add/remove reasons via js). The reason why I''m not using :accessible or some other plugin to ease multimodel forms is that they wants to create a record in Reason, which is good, but they don''t try to reuse it if it already exists. Instead they, of course, will duplicate rows, defeating my purpose. I can post some other code if anybody have some suggestions on how to proceed. Thanks. --~--~----...

I have a host-parasite association matrix in which parasite species are rows and host species columns and cells contain the frequency of interactions. Some parasites are associated with many hosts, and some hosts harbor several parasites, and I want to repeatedly select only one single representative host per "generalized" (multi-host) parasite to create a new matrix in which no hosts

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