Displaying 20 results from an estimated 700 matches similar to: "lmer(): specifying i.i.d random slopes for multiple covariates"
2006 Aug 02
2
lme4 and lmeSplines
I'm trying to use the lmeSplines package together with lme4.
Below is (1) an example of lmeSplines together with nlme (2) an
attempt to use lmeSplines with lme4 (3) then a comparison of the
random effects from the two different methods.
(1)
require(lmeSplines)
data(smSplineEx1)
dat <- smSplineEx1
dat.lo <- loess(y~time, data=dat)
plot(dat.lo)
dat$all <- rep(1,nrow(dat))
times20
2000 Oct 23
4
More mdct questions
Sorry for starting another topic, this is actually a reply to Segher's post
on Sun Oct 22 on the 'mdct question' topic. I wasn't subscribed properly
and so I didn't get email confirmation and thus can't add to that thread.
So Segher, if the equation is indeed what you say it is, then replacing
mdct_backward with this version should work, but it doesn't.
Am I applying
2011 Aug 01
3
formula used by R to compute the t-values in a linear regression
Hello,
I was wondering if someone knows the formula used by the function lm to compute the t-values.
I am trying to implement a linear regression myself. Assuming that I have K variables, and N observations, the formula I am using is:
For the k-th variable, t-value= b_k/sigma_k
With b_k is the coefficient for the k-th variable, and sigma_k =(t(x) x )^(-1) _kk is its standard deviation.
2002 May 06
2
A logit question?
Hello dear r-gurus!
I have a question about the logit-model. I think I have misunderstood
something and I'm trying to find a bug from my code or even better from my
head. Any help is appreciated.
The question is shortly: why I'm not having same coefficients from the
logit-regression when using a link-function and an explicite transformation
of the dependent. Below some details.
I'm
2008 Nov 21
1
Wishlist: fix error in documentation for body<- (PR#13318)
Full_Name: Fabian Scheipl
Version: 2.8.0
OS: Windows, Linux
Submission from: (NULL) (138.246.7.150)
It seems to me that the documentation for body<- is wrong.
The help file for
body(fun, envir = environment(fun)) <- value
says that:
value can be an expression or a list of R expressions.
This produces errors however:
################################
> f <- function(x){}
>
2003 Nov 15
2
Using the rsync checksums for handling large logfiles.
Dear all,
I've only just joined this list, but I can't find any mention of this
idea anywhere else, so I thought I'd just post here before getting too
deep into programming and possibly reinventing the wheel.
Here at Aber, we have around 30 unix and linux servers doing core services.
Each one is maintaining its own logfiles and, for various reasons, we want to
keep these on the
2002 Feb 06
4
Weighted median
Is there a weighted median function out there similar to weighted.mean()
but for medians? If not, I'll try implement or port it myself.
The need for a weighted median came from the following optimization
problem:
x* = arg_x min (a|x| + sum_{k=1}^n |x - b_k|)
where
a : is a *positive* real scalar
x : is a real scalar
n : is an integer
b_k: are negative and positive scalars
2007 Sep 12
1
Verifying understanding of backup-dir vs compare-dest
Hello,
Say one starts with creating an archive
rsync work -> archive
and periodically (below, i = 1 to N) does
rsync --backup-dir=a_<i> work -> archive
and rsync --compare-dest=archive work -> b_<i>
Then suppose one wants to recover the work directory as it was at
time k.
Using the b_<i> directories, one would merely merge
2006 Jul 20
1
Loss of numerical precision from conversion to list ?
I?m working on an R-implementation of the simulation-based finite-sample null-distribution of (R)LR-Test in Mixed Models (i.e. testing for Var(RandomEffect)=0) derived by C. M. Crainiceanu and D. Ruppert.
I'm in the beginning stages of this project and while comparing quick and dirty grid-search-methods and more exact optim()/optimize()-based methods to find the maximum of a part of the
2006 Oct 20
1
Translating lme code into lmer was: Mixed effect model in R
This question comes up periodically, probably enough to give it a proper
thread and maybe point to this thread for reference (similar to the
'conservative anova' thread not too long ago).
Moving from lme syntax, which is the function found in the nlme package,
to lmer syntax (found in lme4) is not too difficult. It is probably
useful to first explain what the differences are between the
2001 Jan 02
0
mdct explanation
...as promised.
This describes the mdct used in my d.m.l patch. I think it is the
same as the Lee fast-dct.
I typed it in a kind of pseudo-TeX, 'cause the ascii art would
kill me. Hope you can read TeX source; if not, ask someone who
can to make a .ps/.gif/.whatever of the TeX output, and put it
on a webpage or something. I'm to lazy to do it (and besides, I
don't have access to TeX,
2004 May 25
0
(OT) Fourier coefficients.
This posting has nothing to do with R (except maybe that I am using R
very heavily in writing the paper to which the question pertains.) I
simply wish to draw upon the impressive knowledge and wisdom of the R
community.
Since this question is way off topic, if anybody has the urge to
reply, they should probably email me directly:
rolf at math.unb.ca
rather than via this list.
My question
2011 Apr 27
0
spikeSlabGAM
spikeSlabGAM_0.9-6 (initial public release)
spikeSlabGAM implements Bayesian variable selection, model choice,
and regularized estimation in (geo-)additive mixed models for
Gaussian, binomial, and Poisson responses.
Its purpose is (1) to choose an appropriate subset of potential
covariates and their interactions, (2) to determine whether linear
or more flexible functional forms (P-splines,
2011 Apr 27
0
spikeSlabGAM
spikeSlabGAM_0.9-6 (initial public release)
spikeSlabGAM implements Bayesian variable selection, model choice,
and regularized estimation in (geo-)additive mixed models for
Gaussian, binomial, and Poisson responses.
Its purpose is (1) to choose an appropriate subset of potential
covariates and their interactions, (2) to determine whether linear
or more flexible functional forms (P-splines,
2006 Jun 06
1
Problems using quadprog for solving quadratic programming problem
Hi,
I'm using the package quadprog to solve the following quadratic programming problem.
I want to minimize the function
(b_1-b_2)^2+(b_3-b_4)^2
by the following constraints b_i, i=1,...,4:
b_1+b_3=1
b_2+b_4=1
0.1<=b_1<=0.2
0.2<=b_2<=0.4
0.8<=b_3<=0.9
0.6<=b_4<=0.8
In my opinion the solution should be b_1=b_2=0.2 und b_3=b_4=0.8.
Unfortunately R doesn't find
2006 Oct 17
2
Mixed effect model in R
Hi,
I am analysing an experiment that has one fixed (6 conditions) and two
random factors (11 subjects, 24 images in the conditions). I read somewhere
else that you can also see such a design as a nested experiment with the
hierarchy: subjects -> condition -> image. For some analysis I have one
respond variable and for others I have more. The response variables are
non-normally distributed.
2009 Jan 29
2
ANOVA in R
Hi
I Have a very large dataset that I would like to conduct ANOVA tests on. Im not a very strong programmer so any help would be appreciated.
the format is
Identifier A1 A2 B1 B2 C1 C2 Norm1 Norm2
1234 1 1 NA NA 4 3 NA NA
4567 2 2 4
2000 Oct 20
2
mdct question
Hi,
Can someone tell me which MDCT and invMDCT equation uses? I implemented the
invMDCT one given in
eusipco.corrected.ps file (handed out by Monty way back) and it produces
different time domain samples.
I tried both the FFT method and the slow way directly from the equation and
couldn't reproduce the results
from the original code. This leads me to believe that the forward
MDCT used in
2004 Jan 30
0
coupled statistical models
Can someone point me to the appropriate functions for
fitting multiple statistical models that are coupled
to each other.
The data are measurements of salinity s and temperature t
at stations id and pressures at p as well as surface elevations h
at stations id. The problem is, for any new station, to estimate
s at all p, given t at all p and given h.
If h is ignored, the for each p, there
2008 Dec 13
0
(PR#13318) Wishlist: fix error in documentation for
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There are two issues here, what it