Displaying 20 results from an estimated 1100 matches similar to: "Logistic regression model selection with overdispersed/autocorrelated data"
2003 Oct 01
1
hypergeometric & population estimates
"help"
We want to estimate the number of caribou in Jasper. We recently conducted
an aerial survey and saw 70 uncollared caribou and 8 of 11 collared
caribou. We want to estimate the number of caribou in this population with
95% confidence limits. Gary White uses the hypergeometric distribution and
determines the population estimates using maximum likelihood and 95%CL as
2003 Jul 04
1
Quasi AIC
Dear all,
Using the quasibinomial and quasipoisson families results in no AIC being
calculated. However, a quasi AIC has actually been defined by Lebreton et al
(1992). In the (in my opinon, at least) very interesting book by Burnham and
Anderson (1998,2002) this QAIC (and also QAICc) is covered. Maybe this is something
that could be implemented in R.
Take a look at page 23 in this pdf:
2008 May 07
2
Estimating QAIC using glm with the quasibinomial family
Hello R-list. I am a "long time listener - first time caller" who has
been using R in research and graduate teaching for over 5 years. I
hope that my question is simple but not too foolish. I've looked
through the FAQ and searched the R site mail list with some close hits
but no direct answers, so...
I would like to estimate QAIC (and QAICc) for a glm fit using the
2010 Oct 07
2
How do I set the dispersion parameter in poisson glm?
Dear R users,
I would like to fit a glm with Poisson distribution and log link with a known dispersion parameter. I do not want to estimate the dispersion parameter. I know what it is, so I simply want to fix it at a constant for this and other models to follow. My simple, no covariate model is:
Tall.glm<-glm(Seedling~1,
family=poisson,
offset(log(area)),
data=tallPSME.df)
I want to
2011 Jan 27
1
Quasi-poisson glm and calculating a qAIC and qAICc...trying to modilfy Bolker et al. 2009 function to work for a glm model
Sorry about re-posting this, it never went out to the mailing list when I
posted this to r-help forum on Nabble and was pending for a few days, now
that I am subscribe to the mailing list I hope that this goes out:
I've been a viewer of this forum for a while and it has helped out a lot,
but this is my first time posting something.
I am running glm models for richness and abundances. For
2005 Dec 09
1
Residuals from GLMMs in the lme4 package
Hello there
This is the first time I have used r-help message board so I hope I have got
the right address.
I am trying to check the residuals of a GLMM model(run using the package
lme4). I have been able to check the residiuals of REMLs in lme4 using the
following:
m1<-lmer(vTotal~Week+fCollar+ (1|fCat), collars)
res<-resid(m1)
plot(res)
qqnorm(res)
library(MASS)
par(mfrow=c(2,3))
2011 Sep 29
1
How to Code Random Nested Variables within Two-way Fixed Model in lmer or lme
Hi All,
I am frustrated by mixed-effects model! I have searched the web for
hours, and found lots on the nested anova, but nothing useful on my
specific case, which is: a random factor (C) is nested within one of the
fixed-factors (A), and a second fixed factor (B) is crossed with the
first fixed factor:
C/A
A
B
A x B
My question: I have a functioning model using the aov command (see
2012 Jul 07
4
replacement has length zero
I have been working on the following code but keep getting an err message. My
current thinking is that the problem is on the indexing but do not know how
to fix it. Any help please?
ungulate <- read.csv("Ungulate.csv",row.names=1)
ungulate <-
as.matrix(ungulate);colnames(ungulate)<-NULL;rownames(ungulate)<-NULL
habitat <- read.csv("Ungulate_vegetation.csv")
2006 Jun 08
2
nested mixed-effect model: variance components
Dear listers,
I am trying to assess variance components for a nested, mixed-effects
model. I think I got an answer that make sense from R, but I have a
warning message and I wanted to check that what I am looking at is
actually what I need:
my data are organized as transects within stations, stations within
habitats, habitats within lagoons.
lagoons: random, habitats: fixed
the question is:
2002 Jul 11
2
Nested anovas in R not doing what they ought to...
Hi, there
I first sent this e-mail a couple months ago, to no avail.Since I am not a member on your mailing list, so could you please cc: a response to me? I'll be sure to check the list today for replies.
I am currently attempting to perform an ANOVA with both nested and normal factors. My problem is that R is treating my nested factors the exact same way as it would interaction terms.
2010 Oct 21
2
nested anova
Hello all,
Can any of you R gurus help me out? I?m not all that great at stats to
begin with, and I?m also learning the R ropes (former SAS user).
Here?s what I need help with? I have a nested sample design and ran a
nested anova, but I don?t know how to interpret the results
habitat (four different types) is nested in site (three types), and site is
nested in gear (two types)
2013 Apr 26
2
Remove reciprocal data from a grouped animal social contact dataset
Hi r-help forum,
I have been collecting contact data (with proximity logger collars)
between a few different species of animal. All animals wear the
collars, and any contact between the animals should be detected and
recorded by both collars. However, this isn't always the case and more
contacts may be recorded on one collar of the two. This is fine, it
depends on battery life and other
2009 May 29
1
data manipulation involving aggregate
hi all,
I often have a data frame like this example
data.frame(sq=c(1,1,1,2,2,3,3,3,3),area=c(1,2,3,1,2,3,1,2,3),habitat=c("garden","garden","pond","field","garden","river","garden","field","field"))
for each "sq" I have multiple "habitat"s each with an associated "area".
I
2012 Oct 26
1
Openbugs- Array Index
Hi,
I'm working on the codes below however every time I run them when they get
to OpenBUGS I keep getting the error message: array index is greater than
array upper bound for hab.
Any help would be greatly appreciated,
Suzie
Codes:
ungulate <- read.csv(file.choose ()) #ungulate
ungulate <-
as.matrix(ungulate);colnames(ungulate)<-NULL;rownames(ungulate)<-NULL
2013 Nov 07
2
Error running MuMIn dredge function using glmer models
Dear list,
I am trying to use MuMIn to compare all possible mixed models using the dredge function on binomial data but I am getting an error message that I cannot decode. This error only occurs when I use glmer. When I use an lmer analysis on a different response variable every works great.
Example using a simplified glmer model
global model:
mod<- glmer(cbind(st$X2.REP.LIVE,
2012 Jan 09
2
Unexpected results using the oneway_test in the coin package
Dear fellow R users,
Keywords: Kruskal-Wallis, Post-Hoc, pair-wise comparisons, Nemenyi-Damico-Wolfe-Dunn test, coin package, oneway_test
I am using the "oneway_test" function in the R package "coin" and I am obtaining results which I cannot believe are accurate. I do not wish to waste anyone's time and so if the following problem is rather trivial, I apologize, however I
2012 Sep 12
7
multinomial MCMCglmm
Dear all,
I would like to add mixed effects in a multinomial model and I am trying
to use MCMCglmm for that.
The main problem I face: my data set consits of a trapping data set,
where the observation at eah trap (1 or 0 for each species) have been
aggregated per traplines. Therefore we have a proportion of
presence/absence for each species per trapline.
ex:
ID_line mesh habitat Apsy Mygl
2017 Nov 15
1
Rasterize function with maximum in R
Hi all,
I have some concerns regarding the rasterize option in R and I would like to know if the fun=max in rasterize in R provides similar results to the one achieved by using "Polygon to Raster using maximum-combined-area" in ArcGIS?
I'm trying to rasterize a habitat layer to a raster of 10m spatial resolution using the function 'max' (e.g. r <- rasterize(ht, r,
2010 Nov 12
2
minimum AIC mixed model selection
Hi!
I am trying to know which habitat variables most affect bird counts in a radius of 100m. I obtained bird counts in 2751 spatial points, and measured percentage of 21 habitat variables in these points.
I applied a mixed model using the "lmer" function to these data, but I do not know how to select the best model using AIC here. Is there a way to do this automatically with R?
2009 Mar 10
1
help structuring mixed model using lmer()
Hi all,
This is partly a statistical question as well as a question about R, but I am stumped!
I have count data from various sites across years. (Not all of the sites in the study appear in all years). Each site has its own habitat score "habitat" that remains constant across all years.
I want to know if counts declined faster on sites with high "habitat" scores.
I can