Displaying 20 results from an estimated 1000 matches similar to: "Mixed-effects models: question about the syntax to introduce interactions"
2011 Oct 25
1
Unlist alternatives?
dfhfsdhf at ghghgr.com
I ran a simple lme model:
modelrandom=lmer(y~ (1|Test) + (1|strain), data=tempsub)
Extracted the BLUPs:
blups=ranef(modelrandom)[1]
Even wrote myself a nice .csv file....:
write.csv(ranef(modelrandom)[1],paste(x,"BLUPs.CSV"))
This all works great. I end up with a .csv file with the names of my strains
in the first column and the BLUP in the second
2011 Nov 11
3
Combining Overlapping Data
I've scoured the archives but have found no concrete answer to my question.
Problem: Two data sets
1st data set(x) = 20,000 rows
2nd data set(y) = 5,000 rows
Both have the same column names, the column of interest to me is a variable
called strain.
For example, a strain named "Chab1405" appears in x 150 times and in y 25
times...
strain "Chab1999" only appears 200
2008 Apr 07
1
problem- Unable To Locate DLL
Hi
I am trying to install "lme4" package, but have
problems intalling matrix package. I get the following
error:
RGui: Rgui.exe -Unable To Locate DLL
the dynamic link library Rblas could not found in the
specified path C:\Program
2005 Oct 26
2
AOV with repeated measures
Dear R user,
I have a question on using R to analyze data with repeated measurements. I
have 2 species with several strains (12) per species, each of which has
been measured twice with for a given trait. No particular covariance, just
two measures. Now I want to analyze the data with an ANOVA (aov)
considering these repeated measures to get the MSq and SSq for the species
and strain level. I
2010 Apr 01
0
model set up question
I need to compare gene expression differences between multiple line pairs of
alcohol preferring and non-preferring rat lines. I have 5 such line pairs, 3
are unrelated but two were derived independently from the same parent stock.
For each line, there are 10 samples. I'll be testing multiple genes, but for
simplicity assume just one gene whose expression is measures as
geneExpression.
Alcohol
2010 Nov 17
0
Cox model output & hazard ratios
Dear R users,
Here is the coxme output I obtain on my survival dataset having 3 strains
and 2 infection status (i: infected, ni: non infected)
coxme(Surv(lay) ~ infection*strain, data=datalay, random= ~1 |block)
Cox mixed-effects model fit by maximum likelihood
Data: datalay
n= 1194
Iterations= 3 77
NULL Integrated Penalized
Log-likelihood -7270.028 -7223.859 -7218.175
2003 Oct 09
1
nlme & lme for complex mixed ANOVAs
Dear List,
I downloaded R for the first time yesterday, in the hopes that I might
deal more effectively with a complex repeated measures experimental
design involving inbred strains of laboratory mice. The design below,
somewhat simplified, cannot be computed with standard ANOVA, because
something called the X'X matrix is too large. The design has the
following factors:
Between-subject
2008 Jan 22
2
extension to nlme self start SSmicmen?
Dear list,
Has anyone created a version of SSmicmen that allows testing for group
differences? The basic Michaelis-Menten equation is:
(Bmax * X) / (Kd + X).
The nlme package allows modeling of random effects for Bmax and Kd as
needed, but I curious how I can build in group differences? I have
receptor binding data for strains of mice, and following Pinheiro and
Bates' lead in their
2008 Feb 04
0
Multiple comparisons and letter assignments
Good morning,
I'm trying to write a function to assign the mean separation grouping
letters to the factors of an experiment. A client wants this so I
thought I'd write my own function for future use. But I'm having
trouble doing it because I don't understand the logic of the
assignment. As a general example, consider the following data and the
results from SAS and its weak
2009 Sep 23
1
re peated measures
Hi,
I am performing a repeated measures 2-way ANOVA to assess the influence of
plant and leaf on aphid fecundity. Fecundity is measured for each aphid on a
single leaf.
Here is what I typed.
wingless <- reshape(Wingless,
varying =
2011 Dec 04
1
Complex multiple t tests in a data frame with several id factors
I have assayed the concentrations of various metal elements in
different anatomic regions of two strains of mice. Now, for each
element, in each region, I want to do a t test to find whether there
is any difference between the two strains.
Here is what I did (using simulated data as an example):
# create the data frame
> elemconc = data.frame(expand.grid(id=1:3, geno=c('exp',
2012 Feb 10
0
a) t-tests on loess splines; b) linear models, type II SS for unbalanced ANOVA
Dear all,
I have some questions regarding the validity an implementation of
statistical tests based on linear models and loess. I've searched the
R-help arhives and found several informative threads that related to my
questions, but there are still a few issues I'm not clear about. I'd be
grateful for guidance.
Background and data set:
I wish to compare the growth and metabolism
2007 Nov 15
5
Multiply each column of array by vector component
Hi,
I've got an array, say with i,jth entry = A_ij, and a vector, say with jth
entry= v_j. I would like to multiply each column of the array by the
corresponding vector component, i,e. find the array with i,jth entry
A_ij * v_j
This seems so basic but I can't figure out how to do it without a loop.
Any suggestions?
Michal.
2017 Jul 19
0
Redundancy canonical analysis plot problem in 3D using VEGAN, RGL, SCATTERPLOT3D and SFSMISC
We need to keep the discussion on the list. When I run your code, there are several problems.
strain.data <- read.xlsx("Dee rhiz.xlsx", sheetName ="strain", header = T, row.names = 1)
str(strain.data) # lists 9 columns at the end with all NAs
strain.data1 <- (strain.data, sqrt.dist = TRUE) # this is not a valid R line. I get
Error: unexpected ',' in
2003 Apr 02
2
lme parameterization question
Hi,
I am trying to parameterize the following mixed model (following Piepho
and Ogutu 2002), to test for a trend over time, using multiple sites:
y[ij]=mu+b[j]+a[i]+w[j]*(beta +t[i])+c[ij]
where:
y[ij]= a response variable at site i and year j
mu = fixed intercept
Beta=fixed slope
w[j]=constant representing the jth year (covariate)
b[j]=random effect of jth year, iid N(0,sigma2[b])
a[i]=random
2002 Sep 12
1
Problem with indexing
Dear List
I am having a bit of a problem getting a program to work.
For each of i=1 to n persons I have a matrix (different for each person) with
m rows.
What I want to do, is create m new data sets such that the first is made up
of the first row for each person from the original matrices, the second
contains the second row for each person from the original matrices etc etc up
to the mth
2006 Sep 21
1
survival function with a Weibull dist
Hi
I am using R to fit a survival function to my data
(with a weibull distribution).
Data: Survival of individuals in relation to 4
treatments ('a','b','c','g')
syntax:
---- > survreg(Surv(date2)~males2, dist='weibull')
But I have some problems interpreting the outcome and
getting the parameters for each curve.
--------- Value Std.
2010 Dec 16
1
defining a formula method for a weighted lm()
In the vcdExtra package on R-Forge, I have functions and generic methods
for calculating log odds ratios
for R x C x strata tables. I'd like to define methods for fitting
weighted lm()s to the resulting loddsratio objects,
but I'm having problems figuring out how to do this generally.
# install.packages("vcdExtra", repos="http://R-Forge.R-Project.org")
2017 Jul 18
3
Redundancy canonical analysis plot problem in 3D using VEGAN, RGL, SCATTERPLOT3D and SFSMISC
Hello Sir
I am getting problem in plotting in CCA . Could you please help me? I wrote the below command but I don't know why it is taking only first 5 env data rather than all 9.
> strain.data <- read.xlsx("Dee rhiz.xlsx", sheetName="strain", header = T, row.names = 1)
> env.data <- read.xlsx("Dee rhiz.xlsx", sheetName="env", header = T,
2001 Nov 05
2
apex ??
I would to know if it's possible with R
put an apex on a character ( i.e 10-2 or aij )
Thanks in advance
Damiano
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