Displaying 20 results from an estimated 1000 matches similar to: "SMATR common slopes test"
2010 Oct 14
2
help with an unbalanced split plot
Hi Everyone,
I am trying to analyze a split plot experiment in the field that was
arranged like this:
I am trying to measure the fitness consequences of seed size.
Factors (X):
*Seed size*: a continuous variable, normally distributed.
*Water*: Categorical Levels- wet and dry.
*Density*: Categorical Levels- high, medium and solo
*Plot*: Counts from 1 to 20
The *response variable *(Y) was the
2011 Apr 10
1
survival object
Hi All,
I am trying to do a survivorship analysis with library(survival)from a data
set that looks like this:
I followed a bunch of naturally germinated seedlings of an annual plant from
germination to death (none made it to reproduce, and died in a period of ~60
days after germination.)
I also know the size of the seed of every individual censused. So I am
trying to analyze seedling survival as
2012 May 11
0
Additional info: help with SMATR: help with pairwise comparisons using MA regression?
Also, this works (taking out multcomp=TRUE, multcompmethod="adjusted"):
com.test=ma(Head.W1~Leg.3.1+Site, type="elevation", data=queens)
print(com.test)
....so for some reason it will do an MA regression on all my data
point together, but shows an error when I try to do pairwise
comparisons between groups.
Thank you,
Ioulia
--------
On Fri, May 11, 2012 at 2:09 AM, Ioulia
2012 May 11
0
help with SMATR: help with pairwise comparisons using MA regression?
Hi there,
I've been using the SMATR package to do standardized major axis (SMA)
regression on allometric data, and I've been able to to pairwise
comparisons of slope & elevation between multiple study sites.
Now I'm trying to do the same thing using major axis (MA) regression,
but I'm getting errors (SMATR should be able to do MA as well as SMA
regression for everything,
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,
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.
2009 Feb 16
1
incl.non.slopes=FALSE does not work at predict.lm
Dear all,
I am trying to estimate the prediction from a fixed effects model and their
confidence intervals as well. Though I do not want to include in the
prediction and at the confidence intervals the intercept. For that reason I
used the argument incl.non.slopes=FALSE. But either if it is TRUE or FALSE
it does not have any difference and also the system does not provide any
warning. I really
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
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)
2009 Sep 15
1
Compare a group of line slopes
Hi, all,
I am thinking to compare a group of slopes from regression lines to see if
they are different overall, and then make specific comparisons between
groups. How can I achieve that in R? I searched the archives and there are
only discussions about comparing two lines a time. Thanks.
A sample data set is like the following. I would like to compare the
regression slopes between the five
2010 Nov 06
2
3-way interaction simple slopes
Can anyone show me how to test for significant simple slopes of a 3-way
interaction, with covariates.
my equation
tmod<-(glm(PCL~ rank.f + gender.f + MONTHS + CEXPOSE.M + bf.m +
MONTHS*CEXPOSE.M*bf.m,
data=mhatv, family=gaussian ,na.action=na.omit))
Thank you
Mike
[[alternative HTML version deleted]]
2009 Aug 19
2
lmer with random slopes for 2 or more first-level factors?
I have data from a design in which items are completely nested within
subjects. Subject is the only second-level factor, but I have
multiple first-level factors (IVs). Say there are 2 such independent
variables that I am interested in. What is the proper syntax to fit a
mixed-effects model with a by-subject random intercept, and by-subject
random slopes for both the 2 IVs?
I can
2009 Apr 06
1
Comparing 2 slopes of 2 regression lines
Hello everyone,
I would like to test two regression slopes:do they differ significantly?The data and commands I've used so far:
x<-8.5:32.5 #Vektor x
y<-c( NA , NA , 5.67 , 6.53 , 6.83, 7.41 , 7.93 , 8.5 , 8.86, 9.46 , 9.82 , 10 ,10.35 , 10.7 ,11.03 ,11.37 ,11.61 ,11.84, 12.12, 12.39 ,12.67 ,12.96, 13.28 ,13.47, 13.65) #Vektor y
(regression<-lm(y~x))
summary(regression)
2001 Jul 16
0
FWD: OpenSSH bug in MacOS X
-----Original Message-----
From: Josh Larios [mailto:jdlarios at cac.washington.edu]
Sent: Thursday, July 05, 2001 8:40 PM
To: openssh at openssh.com
Subject: OpenSSH bug in MacOS X
In MacOS X 10.0.4, and probably other versions, getaddrinfo() is broken in
such a way that when you try to connect to certain hosts, openssh fails.
getaddrinfo is first failing the lookup, and then failing to
2006 Aug 24
1
lmer(): specifying i.i.d random slopes for multiple covariates
Dear readers,
Is it possible to specify a model
y=X %*% beta + Z %*% b ; b=(b_1,..,b_k) and b_i~N(0,v^2) for i=1,..,k
that is, a model where the random slopes for different covariates are i.i.d., in lmer() and how?
In lme() one needs a constant grouping factor (e.g.: all=rep(1,n)) and would then specify:
lme(fixed= y~X, random= list(all=pdIdent(~Z-1)) ) ,
that?s how it's done in the
2007 Feb 20
1
testing slopes
Hello
Instead of testing against 0 i would like to test regression slopes against -1. Any idea if there's an R script (package?) available.
Thanks for any hint.
Cheers
Lukas
???
Lukas Indermaur, PhD student
eawag / Swiss Federal Institute of Aquatic Science and Technology
ECO - Department of Aquatic Ecology
?berlandstrasse 133
CH-8600 D?bendorf
Switzerland
Phone: +41 (0) 71 220
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
2012 May 01
1
testing parallel slopes assumption for Ordinal Logistic Regression
Hi everyone, I'm a bit new here (and new to R), and I was trying to do an
OLR, and testing the parallel slope assumption seems be very important. I
browsed through past postings, and didn't find much to help me in this area.
I was wondering if anyone knew how I could go about doing this. Thank you.
--
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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,
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 <-