Displaying 20 results from an estimated 9000 matches similar to: "The test of randomized slopes(intercepts)"
2006 Aug 16
1
[SPAM] - RE: REML with random slopes and random intercepts giving strange results - Bayesian Filter detected spam
Can you provide the summary(m2) results?
> -----Original Message-----
> From: Simon Pickett [mailto:S.Pickett at exeter.ac.uk]
> Sent: Wednesday, August 16, 2006 7:14 AM
> To: Doran, Harold
> Cc: r-help at stat.math.ethz.ch
> Subject: [SPAM] - RE: [R] REML with random slopes and random
> intercepts giving strange results - Bayesian Filter detected spam
>
> Hi again,
2013 Oct 09
0
lme slopes and intercepts differences
Hello all,
I need to infer if the slopes and intercept of each group of my lme analyze,
showed below, are different from each other. Like a Tukey test. I don't
need to compare the slope and interceptof each subject of my fixed data,
but the slope and intercept of each group of them.
> m1<-lme(fvfm~term*sp*env*est*time,random=~term|id,table)
You know how can I make it?
Thanks for
2011 Jul 18
1
question about linear mixed model
Hi all:
I have a question about linear mixed model.
my linear mixed model with randomized slope and intercept with interaction
of time and group(g1,g2,g3):
model<- glmmPQL(log10(CD4) ~ time + factor(group)+ time:factor(group),
random = ~time|id)
What I get is only the main and interaction of time and group.My question
is:
1. How can I get the g1,g2,g3's slope respectively?In other
2012 Mar 09
0
pdMat class in LME to mimic SAS proc mixed group option? Group-specific random slopes
I would like to be able to use lme to fit random effect models In which some but not all of the random effects are constrained to be independent. It seems as thought the pdMat options in lme are a promising avenue. However, none of the existing pdMat classes seem to allow what I want.
As a specific example, I would like to fit a random intercept/slope mixed model to longitudinal observations in
2001 Oct 08
3
testing diff for slopes and intercepts
I fit the model
fit<-lm(thresh~cond*Ne)
where
thresh is the reponse
cond is a factor with levels a, b, and c
Ne is a continuous indep var
I think of this full model as having three lines: thresh as a function of
Ne for each condition. Thus we have slopea, slopeb, slopec, inta, intb,
intc.
lm output my params
-------------------------
(Intercept) inta
condb intb - inta
condc
2006 Oct 30
1
Random intercept-slope correlation (nlme)
Dear list members,
I am working with a multilevel growth curve, that in its simplest form goes
like follows:
Yit = Ai + Bi t + eit (the error term is assumed to follow an AR(1)
autorregressive process)
One major topic in my research is the convergence in the values of Y over
time. Thus, I am interested in the relationship between the random effects
for the intercept and the slope, and I
2008 May 16
1
Making slope coefficients ``relative to 0''.
I am interested in whether the slopes in a linear model are different
from 0.
I.e. I would like to obtain the slope estimates, and their standard
errors,
``relative to 0'' for each group, rather than relative to some baseline.
Explicitly I would like to write/represent the model as
y = a_i + b_i*x + E
i = 1, ..., K, where x is a continuous variate and i indexes groups
(levels of a
2010 Oct 18
0
specifying lme function with a priori hypothesis concerning between-group variation in slopes
I want to specify a 2-level mixed model using the lme function in order to
test an a priori hypothesis about the between-group values of the slopes but
don't know how to do this . Here is the problem.
Consider first the case of a single group. The model is: Y_i= a +bX_i +
error where I indexes the different values of X and Y in this group . The
a priori hypothesis of the slope is: b=K.
2011 Dec 13
8
How to compute 95%CI for OR from logistic regression?
Hi all:
My data has 3 variables:
age(3levels : <30y=1 30-50y=2, >50y=3)
gender(Male=0, Female=1)
CD4 cell count(raw lab measurement)
y(1:death 0:alive)
I perform logistic regression to find out the factors that influence y.
result<-glm(y ~ factor(age) + factor(gender) + CD4,family = binomial)
>From the result,I can get OR(Odds Ratio) of gender via exp(Estimate of Female,
2006 Aug 15
1
REML with random slopes and random intercepts giving strange results
Hi everyone,
I have been using REML to derive intercepts and coeficients for each
individual in a growth study. So the code is
m2 <- lmer(change.wt ~ newwt+(newwt|id), data = grow)
Calling coef(model.lmer) gives a matrix with this information which is
what I want. However, as a test I looked at each individual on its own and
used a simple linear regression to obtain the same information, then
2004 Mar 29
2
Confidence Intervals for slopes
Hi,
I'm trying to get confidence intervals to slopes from a linear model
and I can't figure out how to get at them. As a cut 'n' paste example:
#################
# dummy dataset - regression data for 3 treatments, each treatment with
different (normal) variance
x <- rep(1:10, length=30)
y <- 10 - (rep(c(0.2,0.5,0.8), each=10)*x)+c(rnorm(10, sd=0.1),
rnorm(10,
2009 Apr 10
0
Didactic example and doubt: how to compare two regression line slopes
Hi,
I read almost all I found in prior R-Help list about How to compare
two regression line slopes.
So, I made a didactic example to illustrate a solution cited by Ben Bolker:
===============================================
Subject: Re: [R] How to compare two regression line slopes
From: Ben Bolker (bol... at ufl.edu)
Date: Jan 27, 2009 1:52:20 pm
List: org.r-project.r-help
2010 Sep 13
2
Homogeneity of regression slopes
Hello,
We've got a dataset with several variables, one of which we're using
to split the data into 3 smaller subsets. (as the variable takes 1 of
3 possible values).
There are several more variables too, many of which we're using to fit
regression models using lm. So I have 3 models fitted (one for each
subset of course), each having slope estimates for the predictor
variables.
2010 Nov 06
1
SMATR common slopes test
Hi All,
I am confused with SMATR's test for common slope. My null hypothesis here is
that all slopes are parallel (common slopes?), right?
So if I get a p value < 0.05 means that we can have confidence to reject it?
That slopes are different?
Or the other way around? it means that we have statistical confidence that
the slopes are parallel?
thanks
--
Eugenio Larios
PhD Student
University
2006 Nov 01
1
Compare linear regressios for significant differences of the slopes
Hi
I have (8 measures * 96 groups) = 768 datasets for which I did linear
regressions using lm().
Now I want to compare the slopes for each of the 8 measures in each of
the 96 groups. As I understand , I can not use
> anova(lm1, ..., lm8)
as the lm1 ... lm8 are based on different datasets.
I also read in previous discussions in this list, that I can see if the
slope +- stddev(slope)
2002 Jul 23
0
Comparing slopes of several linear models
Dear all
I have the following data (a shortened extract
shown; some replictates of time deleted) to which I
fitted the linear model given below:
time group mass
11 control 0.019
11 control 0.014
14 control 0.0306
14 control 0.0289
14 control 0.0236
17 control 0.0469
17 control 0.0709
11 five 0.0077
11 five
2008 Apr 13
1
plotting muliple CI ellipses for EB estimates
I have empirical Bayes estimates for slopes and intercepts for a number of
subjects and I would like to plot the slopes and intercepts with confidence
ellipses. These ellipses would be based on the confidence intervals for the
slope and intercepts (forming the major and minor axis of each ellipse), and
the correlation in the slope and intercepts.
The ellipse function in the car library
2003 Jul 21
5
how to test whether two slopes are sign. different?
Not really r-specific:
Z = (b1 - b2) / SQRT ( SEb1^2 + SEb2^2)
-------Original Message-------
From: Gijsbert Stoet <stoet at volition.wustl.edu>
Sent: 07/20/03 09:51 PM
To: r-help at stat.math.ethz.ch
Subject: [R] how to test whether two slopes are sign. different?
>
> Hi,
suppose I do want to test whether the slopes (e.g. determined with
lsfit) of two different population are
2010 Aug 26
1
Random slopes in lmer
Hi
I want to extract the random slopes from a lmer (I am doing a random regression), but are the answers obtained from ranef or coef?
My model is: mod1<-lmer(B~ A +(A|bird), family=quasibinomial)
And I want to obtain a slope for each individual bird but am not sure which output I need and can't find the answer anywhere.
Thanks
Sam
Dr Samantha Patrick
EU INTERREG Post Doc
Davy 618
2009 Jan 27
3
How to compare two regression line slopes
Hi,
I've made a research about how to compare two regression line slopes
(of y versus x for 2 groups, "group" being a factor ) using R.
I knew the method based on the following statement :
t = (b1 - b2) / sb1,b2
where b1 and b2 are the two slope coefficients and sb1,b2 the pooled
standard error of the slope (b)
which can be calculated in R this way:
> df1 <-