Displaying 20 results from an estimated 4000 matches similar to: "distribution for random effects?"
2010 Jul 20
1
logistic regression with repeated measures for species-habitat associations
Hi,
I have three years of species presence/absence data for a set of ~100
ponds, with a list of associated habitat characteristics (park, vegetation,
hydroperiod, etc.). The datasets differ slightly by year because some ponds
were dry in some years and not in others. My goal is to look at habitat
associations for a couple focal species.
For each year, I have a data table that looks like
2009 Feb 24
2
lmer, estimation of p-values and mcmcsamp
(To the list moderator: I just subscribed to the list. Apologies for not
having done so longer before trying to post.)
Hi all,
I am currently using lmer to analyze data from an experiment with a
single fixed factor (treatment, 6 levels) and a single random factor
(block). I've been trying to follow the online guidance for estimating
p-values for parameter estimates on these and other
2012 Jun 21
3
Exporting data from R into an Excel File on Mac
Dear R Professionals,
I am currently an intern at the University of Rhode Island and I need to
know how to export data from R into an Excel file. As it is my
understanding, xlsReadWrite is not available for mac. Is there another
package available for mac users to be able to perform this function.
Sincerely,
Maureen J Hayden
University of Rhode Island
Class of 2015
Marine Biology Major
2011 May 13
1
using glmer to fit a mixed-effects model with gamma-distributed response variable
Sub: using glmer to fit a mixed-effects model with gamma-distributed
response variable
Hello,
I'm currently trying to fit a mixed effects model , i.e.:
> burnedmodel1.2<-glmer(gpost.f.crwn.length~lg.shigo.av+dbh+leaf.area+
bark.thick.bh+ht.any+ht.alive+(1|site/transect/plot), family=gaussian,
na.action=na.omit, data=rws30.BL)
If I run this code, I get the error below:
Error:
2011 Apr 28
1
using lme4 with three nested random effects
Hi all,
I'm trying to fit models for data with three levels of nested random
effects: site/transect/plot. For example,
modelincrBS<-glmer(l.ru.ba.incr~shigo.av+pre.f.crwn.length+bark.thick.bh+Date+slope.pos.num+dens.T+dbh+leaf.area+can.pos.num+(1|site/transect/plot),
data=rws30.UL, family=gaussian, na.action=na.omit)
but I get the following error:
Error: length(f1) == length(f2) is not
2008 Aug 25
1
Specifying random effects distribution in glmer()
I'm trying to figure out how to carry out a Poisson regression fit to
longitudinal data with a gamma distribution with unknown shape and
scale parameters.
I've tried the 'lmer4' package's glmer() function, which fits the
Poisson regression using:
library('lme4')
fit5<- glmer(seizures ~ time + progabide + timeXprog +
offset(lnPeriod) + (1|id),
data=pdata,
2008 Jul 19
1
wroung groupedData despite reading Bates and Pinheiro 3 times
Hi everyone. I am trying to add a formula to my data using the groupedData
function.
My experiment consists of randomized block design using fruits, vegetation
and time as factors. The idea is to see if fruits, vegetation and time
explain the abundance of mice. I am using tree density as a covariate.
So I tried to fit the following structure to my data.
>
2007 Aug 28
1
subcripts on data frames (PR#9885)
I'm not sure if this is a bug, or if I'm doing something wrong.
=20
=46rom the worms dataframe, which is at in a file called worms.txt at
=20
http://www.imperial.ac.uk/bio/research/crawley/therbook
<http://www.imperial.ac.uk/bio/research/mjcraw/therbook/index.htm>=20
=20
the idea is to extract a subset of the rows, sorted in declining order
of worm density, with only the maximum
2019 Mar 26
1
IMAP coredumps for one user
FreeBSD-12
Dovecot-2.3.5
I am having problems with one use
Mar 25 21:30:12 imap(gau.mon at crownkenya.com)<91364><U7qCZO+ECfCaRh6E>:
Fatal: master: service(imap): child 91364 killed with signal 6 (core dumped)
Mar 25 21:30:14 imap(gau.mon at crownkenya.com)<2381><moHYZO+EDvCaRh6E>:
Fatal: master: service(imap): child 2381 killed with signal 6 (core dumped)
Mar 26 06:29:26
2008 Jul 06
1
What is my replication unit? Lmer for binary longitudinal data with blocks and two treaments.
First I would like to say thank you for taking the time to read it.Here is my
problem.
I am running a lmer analysis for binary longitudinal (repeated measures)
data.
Basically, I manipulated fruits and vegetation to two levels each(present
and absent) and I am trying to access how these factors affect mice foraging
behavior. The design consist of 12 plots, divided in 3 blocks. So each
block
2012 Oct 04
4
Creating vegetation distance groups from one column
Hi R listers,
I am trying to group distances of nests to the vegetation into classes that
are define by (0-5m, 6-10m, 11-15m, 16-20m, 21-25m, 26-30m, 31-35m, 36-40m,
41-45m, 46-50m, 51-55m, 56-60m). Each row is a nest and all the distances to
the vegetation is in a column.
In plyr, I have tried - below script but I think I am going about this the
wrong way and am not successful.
#Veg index
2010 Sep 24
1
Fitting GLMM models with glmer
Hi everybody:
I?m trying to rewrite some routines originally written for SAS?s PROC
NLMIXED into LME4's glmer.
These examples came from a paper by Nelson et al. (Use of the
Probability Integral Transformation to Fit Nonlinear Mixed-Models
with Nonnormal Random Effects - 2006). Firstly the authors fit a
Poisson model with canonical link and a single normal random effect
bi ~ N(0;Sigma^2).The
2010 Oct 24
1
best predictive model for mixed catagorical/continuous variables
Would anybody be able to advise on which package would offer the best
approach for producing a model able to predict the probability of species
occupation based upon a range of variables, some of them catagorical (eg.
ten soil types where the numbers assigned are not related to any
qualitative/quantitative continuum or vegetation type) and others continuous
such as field size or vegetation height.
2010 May 26
1
Fill a matrix using logical arguments?
Hello all,
I am going slightly mad trying to create a table for running
co-correspondence analysis.
What I have is seed bank and vegetation data, and my aim is to see if
the vegetation found in a site (containing several seed bank samples)
can predict the composition of a seed bank sample within that site. So
for this I need two tables with matching rows.
I have created an empty matrix,
2010 Nov 12
1
repeated measure test
Hi,
This is a question regarding technique rather than an R specific issue. I
have been asked to evaluate a 30+ year long term continuous survey of bird
presence/absence data that has an associated ocular estimate of the
vegetation community percent coverage. The data are organized by
subpopulations (5), and by year ( 1991 - present). We are interested in
gaining understanding on whether bird
2008 Apr 18
2
Correspondence and detrended correspondence analysis
Hi,
I hope someone knows the answer to this or has a real good reference about it (I am using Legendre & Legendre, Numerical Ecology, 1998).... My data is a data.frame with locations as rows and vegetation assemblages / species as columns. I've done a PCA, a correspondance analysis (CA) using ca in ca package and a detrended correspondance analysis (DCA) using decorana from vegan package.
2006 Jul 21
2
rpart unbalanced data
Hello all,
I am currently working with rpart to classify vegetation types by spectral
characteristics, and am comming up with poor classifications based on the fact
that I have some vegetation types that have only 15 observations, while others
have over 100. I have attempted to supply prior weights to the dataset, though
this does not improve the classification greatly. Could anyone supply some
2012 Apr 14
2
master thesis
Hi,
For my master thesis I have 24 micro-plots on which I did measurements during 3 months.
The measurements were:
- Rainfall and runoff events throughout 3monts (runoff being dependant on the rainfall, a coefficient (%) has been made per rainfall event and per 3 months)
- Soil texture (3 different textures were differentiated)
- Slope (3 classes of slopes)
- Stoniness (one time measurement)
2008 Feb 04
5
How to search for packages
Hi everybody,
I know this might be very off topic and it took me quite a while to up my courage to post this?. But I remember a thread some time ago about how we can find the packages we need to do specific tasks in R if we don?t know before hand which ones actually do it. Now all the packages are listed alphabetically on the web site. Since I am not very advanced in writing my own functions I
2010 Mar 20
5
Problem specifying Gamma distribution in lme4/glmer
Dear R and lme4 users-
I am trying to fit a mixed-effects model, with the glmer function in
lme4, to right-skewed, zero-inflated, non-normal data representing
understory grass and forb biomass (continuous) as a function of tree
density (indicated by leaf-area). Thus, I have tried to specify a
Gamma distribution with a log-link function but consistently receive
an error as follows:
>