Displaying 20 results from an estimated 2000 matches similar to: "Problems using predict from GAM model averaging (MuMIn)"
2012 Jun 26
2
MuMIn - assessing variable importance following model averaging, z-stats/p-values or CI?
Dear R users,
Recent changes to the MuMIn package now means that the model averaging command (model.avg) no longer returns confidence intervals, but instead returns zvalues and corresponding pvalues for fixed effects included in models.
Previously I have used this package for model selection/averaging following Greuber et al (2011) where it suggests that one should use confidence intervals from
2011 Feb 04
0
GAM quasipoisson in MuMIn - SOLVED
Hi,
Got my issues sorted.
Error message solved:
I heard from the guy who developed MuMIn and his suggestion worked.
"As for the error you get, it seems you are running an old version of MuMIn.
Please update the package first."
I did (I was only 1 version behind in both R and in MuMIn) and error
disappeared!
Running quasipoisson GAM in MuMIn:
As for my questions on GAM and " to
2011 Feb 04
1
GAM quasipoisson in MuMIn
Hi,
I have a GAM quasipoisson that I'd like to run through MuMIn package
- dredge
- gettop.models
- model.avg
However, I'm having no luck with script from an example in MuMIn help file.
In MuMIn help they advise "include only models with smooth OR linear term
(but not both) for each variable". Their example is:
# Example with gam models (based on
2012 May 03
0
Model Averaging Help
Dear All,
I'm using AIC-weighted model averaging to calculate model averaged
parameter estimates and partial r-squares of each variable in a
10-variable linear regression.
I've been using the MuMIn package to calculate parameter estimates, but
am struggling with partial r-squares. There doesn't seem to be any
function in the MuMIn package dealing with partial r-square
2024 Feb 07
1
[EXTERNAL] Re: NOTE: multiple local function definitions for ?fun? with different formal arguments
I put the idea below into a function that gives nicer looking results.
Here's the new code:
dupnames <- function(path = ".") {
Rfiles <- pkgload:::find_code(path)
allnames <- data.frame(names=character(), filename=character(), line
= numeric())
result <- NULL
for (f in Rfiles) {
exprs <- parse(f, keep.source = TRUE)
locs <-
2011 Aug 10
2
join columns
Dear R-help,
I wonder if you could give me some suggestions in how to do a union
join of two data frames as follow:
-> union join the common column, and insert a 0 if one is missing.
I made a function to perform the following, and I know it may not that
quite welly written, but it works.
Any suggestions are welcome, many thanks.
Anthony
> q1 =
2010 Sep 14
1
Model averaging with (and without) interaction terms
I?ve used logistic regression to create models to assess the effect of
3 variables on the presence or absence of a species, including the
interaction terms between variables and model averaging using MuMI:
model.avg
The top models (delta<4) include several models with interaction terms
and some models without; model weights are quite low for all models
(<0.25). My problem is that the models
2014 Jun 26
0
AICc in MuMIn package
Hello,
I am modelling in glmmADMB count data (I´m using a negative binomial
distribution to avoid possitive overdispersion) with four fixed and one
random effect. I´m also using MuMIn package to calculate the AICc and also
to model averaging using the function dredge. What I do not understand is
why dredge calculates a different value of the AICc and degrees of freedom
than the function AICc
2012 Jul 27
0
dredge solely offset models in MuMIn
hello everyone,
I'm modelling in lmer an average chick weight defined as
"Total.brood.mass ~ offset(chick.number), with three fixed and two
random effect. Next, I want to use function dredge from MuMIn package
for model averaging. Not sure why, but in consequence the offset
variable is treated as a predictor, so I get a table that mixes models
with and without that offset term (the first
2004 Dec 10
1
Porting optimisation setup from Excel Solver to R
Hi all,
I am currently optimising a small portfolio I have
created as a part of my research project in Excel. I
am unable to find the appropriate package to port this
into R. My problem set up is as follows
Minimise ABS(Sum(Xi-Xi')+10*Sum(XiMi)/Mavg)
Subject to:
0 <= Xi <= 0.05
ABS(Sum(Xi)) = 0.2
where
Mi - Market Cap of Stock i
Xi - Initial weight of Stock i
Xi' - New weight of
2011 Aug 29
1
MuMIn Problem getting adjusted Confidence intervals
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
2013 Apr 08
0
A categorized list of R functions
Dear Rees Morrison,
Re:
(...)
>
> What additional code would create a table output, with the function name in the left column, sorted alphabetically within a pattern, and the pattern of the function in the column to the right. Users could then sort by those patterns, rename some to suit themselves, etc.
(...)
The version below creates a tab-delimited table with 3 columns: seach
2015 Nov 23
2
Model averaging en R
Hola a todos,
He realizado un dredge (para obtener todos los modelos GAM posibles a parir
de un full model), luego he seleccionado un confidence set (los modelos que
no se diferencian en 2 en AIC) y he hecho un model averaging con ese
confidence set. Ahora me gustaría aplicar ese modelo "average" ajustado
sobre otro set de datos pero no se como especificar en R que use el mismo
modelo
2011 Oct 25
1
difficulties with MuMIn model generation with coxph
Hi All,
I'm having trouble with the automatized model generation (dredge) function
in the MuMIn package. I'm trying to use it to automatically generate subsets
of models from a global cox proportional hazards model, and rank them based
on AICc. These seems like it's possible, and the Mumin documentation says
that coxph is supported. However, when I run the code (see below), it gives
2013 Apr 01
0
Error message in dredge function (MuMIn package) with binary GLM
Hi all,
My replies within the forum aren't getting approved, though my emails
always go through, so here is my reply to a question I previously
posted (all questions and answers shown). Thanks, Cat
I'm having trouble with the model generating 'dredge' function in the MuMIn
'Multi-model Inference' package.
Here's the script:
globalmodel<-
2012 Jun 24
1
MuMIn for GLM Negative Binomial Model
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.
>
> BirdNegBin
2013 Mar 29
2
Error message in dredge function (MuMIn package) used with binary GLM
Hi all,
I'm having trouble with the model generating 'dredge' function in the MuMIn
'Multi-model Inference' package.
Here's the script:
globalmodel<- glm(TB~lat+protocol+tested+
streams+goats+hay+cattle+deer,
family="binomial")
chat<- deviance(globalmodel)/59 #There we 59 residual degrees of freedom in
this global model.
models<- dredge(globalmodel,
2024 Jul 31
1
Difference between stats.steps() and MuMIn.dredge() to select best fit model
Hello,
I try to understand the different approaches how to select the best fit
regression model.
This is not about AIC, BIC, etc. It is about the difference between the
steps() function
(in stats package) and the dredge() function (in MuMIn) package.
I see several examples on the internet.
step() explore the model space with a step wise approach.
And dredge() try out all possible combinations
2010 Oct 12
1
delta AIC for models with 2 variables using MuMIn
Dear List,
I want to ask a AIC question based on package library(MuMIn)
The relative importance of 16 explanatory variables
are assessed using delta AIC in a generalized linear model.
Please kindly advise if it is possible to show models
with any two only certain variables.
Thank you.
Elaine
I asked a similar question and got a great help for models
with only one variable as below.
2012 Jul 11
1
Package MuMIn (dredge): Error in ret[, ] <- cbind(x, se, rep(if (is.null(df)) NA_real_ else df, : number of items to replace is not a multiple of replacement length.
Hello R community,
I am attempting to run multiple logistic regressions (multinomial, via
package 'nnet'), with Automated Model Selection (dredge, package 'MuMIn').
The aim is to reduce the number of predictor variables by assessing relative
performance of each variable, which can be done in a coarse fashion using
the Automated Model Selection option in package 'MuMIn'