Displaying 20 results from an estimated 700 matches similar to: "nested anova"
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.
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
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
2008 Mar 27
1
panel function question
I have two data sets with locations, X, Y of houses (df.house) and
habitats(df.habitat), respectively. In each dataset, there are 3
replicates (Repeat). Because each replicate has different locations of
houses and habitats, I would like to plot them in panels. I wrote
something like this:
mypanel<-function(x,y,subscripts,...){
panel.xyplot(x,y,pch=20)
panel.xyplot(
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
2006 Jul 19
1
Random structure of nested design in lme
All,
I'm trying to analyze the results of a reciprocal transplant experiment using lme(). While I get the error-term right in aov(), in lme() it appears impossible to get as expected. I would be greatful for any help.
My experiment aimed to identify whether two fixed factors (habitat type and soil type) affect the development of plants. I took soil from six random sites each of two types
2011 Dec 21
3
black and white in qplot? layout 4 graphs in one screen
Hello,
I am trying to plot means and standard errors conditioned by a factor, using
qplot. I am successful at getting the bar graph I want with a error bar,
however I have tried many things and cannot get the bars to change colors.
Currently showing as red and blue, but need it to be black and white for
publication. Any suggestions please?
Using a data set June, which is str:
2005 Oct 31
1
GLM
Hello R-users,
I am a relatively new user of R and I have a question regarding glm. I want
to run the function GLM on multiple individuals separately and then get
means for summary statistics such as AIC and coef. Is there a way to do this
in R without separately going through each individual and subsetting the
dataset, getting the summary statistics and averaging them? For example, in
the
2006 Jan 30
4
Logistic regression model selection with overdispersed/autocorrelated data
I am creating habitat selection models for caribou and other species with
data collected from GPS collars. In my current situation the radio-collars
recorded the locations of 30 caribou every 6 hours. I am then comparing
resources used at caribou locations to random locations using logistic
regression (standard habitat analysis).
The data is therefore highly autocorrelated and this causes Type
2009 Aug 26
3
changing equal values on matrix by same random number
Dear all,
I have about 30,000 matrix (512x512), with values from 1 to N.
Each value on a matrix represent a habitat patch on my
matrix (i.e. my landscape). Non-habitat are stored as ZERO.
No I need to change each 1-to-N values for the same random
number.
Just supose my matrix is:
mymat<-matrix(c(1,1,1,0,0,0,0,0,0,0,0,
0,0,0,0,2,2,2,0,0,0,0,
0,0,0,0,2,2,2,0,0,0,0,
3,3,0,0,0,0,0,0,0,4,4,
2017 Jun 21
4
How to apply a system of ordinary differential equations to a cell grid?
Hello,
I am developing an agent-based model to simulate the spread of infectious diseases in heterogeneous landscapes composed of habitat polygons (or clumps of connected cells). To simplify the model, I consider a habitat grid (or raster) containing the polygon ID of each cell. In addition, I have epidemiological parameters associated with each polygon ID. At each time step, the parameter values
2011 Aug 11
1
Mixed effect models
I am using two mixed effect models. Firstly, what I am trying to do is to
compare green roofs abundance with brownfield, green roof with green space
abundance, and finally green
space with brownfield abundance. I am unsure if I have done the
correct model. I have to use a mixed effect model because my data is
nested.
This is the code and output
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