Displaying 20 results from an estimated 100 matches similar to: "Pvalues and lme"
2007 Feb 13
1
lme4/lmer: P-Values from mcmc samples or chi2-tests?
Dear R users,
I have now tried out several options of obtaining p-values for
(quasi)poisson lmer models, including Markov-chain Monte Carlo sampling
and single-term deletions with subsequent chi-square tests (although I
am aware that the latter may be problematic).
However, I encountered several problems that can be classified as
(1) the quasipoisson lmer model does not give p-values when
2007 Feb 12
1
lmer and estimation of p-values: error with mcmcpvalue()
Dear all,
I am currently analyzing count data from a hierarchical design, and I?ve
tried to follow the suggestions for a correct estimation of p-values as
discusssed at R-Wiki
(http://wiki.r-project.org/rwiki/doku.php?id=guides:lmer-tests&s=lme%20and%20aov).
However, I have the problem that my model only consists of parameters
with just 1 d.f. (intercepts, slopes), so that the
2009 Feb 24
2
lmer, estimation of p-values and mcmcsamp
(To the list moderator: I just subscribed to the list. Apologies for not
having done so longer before trying to post.)
Hi all,
I am currently using lmer to analyze data from an experiment with a
single fixed factor (treatment, 6 levels) and a single random factor
(block). I've been trying to follow the online guidance for estimating
p-values for parameter estimates on these and other
2007 Mar 12
2
Lmer Mcmc Summary and p values
Dear R users
I am trying to obtain p-values for (quasi)poisson lmer models, including
Markov-chain Monte Carlo sampling and the command summary.
>
> My problems is that p values derived from both these methods are
totally different. My question is
(1) there a bug in my code and
>
(2) How can I proceed, left with these uncertainties in the estimations of
> the p-values?
>
> Below
2007 Mar 13
1
lme4 and mcmcamp
Dear R users
I am trying to obtain p-values for (quasi)poisson lmer models, using
Markov-chain Monte Carlo sampling and the command summary.
>
> My problems is that p values derived from both these methods are
totally different. My question is
(1) there a bug in my code and
>
(2) How can I proceed, left with these uncertainties in the estimations of
> the p-values?
>
> Below is
2008 Aug 29
1
significance of random effects in poisson lmer
Hi,
I am having problems trying to assess the significance of random terms
in a generalized linear mixed model using lme4 package. The model
describes bird species richness R along roads (offset by log length of
road log_length) as a function of fixed effects Shrub (%shrub cover) and
Width (width of road), and random effect Site (nested within Site
Cluster).
>From reading answers to previous
2009 Dec 07
0
Bootstrap pvalues
Hi,
How do I generate bootstrap p-values for goodness of fit test.
Thank you in advance for your help,
Juliet
[[alternative HTML version deleted]]
2003 Dec 10
2
pvalues
dear all-
If I have a vector of numbers (not necessarily
normally distributed) how can I get the p-value of a
number in this distribution. I am interested in the
"inverse" of 'quantile' .
thank you-
Maya
2009 Aug 28
1
extracting pvalues from ttest
Hello list,
I have a similar issue as this post
http://tolstoy.newcastle.edu.au/R/e6/help/09/04/11438.html#options2 and I
used the suggestion provided by Jorge with modifications to my data
do.call(c,lapply(your_list_with_the_t_tests,function(x) x$p.value))
but I am getting the following error after excuting the code
B<-by(eo,eo$PlateID, function(.sub) t.test(mcp1~Self_T1D,data=.sub,
2011 Jul 04
2
clustering based on most significant pvalues does not separate the groups!
Hi all,
I have some microarray data on 40 samples that fall into two groups. I have
a value for 480k probes for each of those samples. I performed a t test
(rowttests) on each row(giving the indices of the columns for each group)
then used p.adjust() to adjust the pvalues for the number of tests
performed. I then selected only the probes with adj-p.value<=0.05. I end up
with roughly 2000
2005 Mar 15
4
How to extract x rows to get x pvalues using t.test
Hi all,
My data
genes
[,1] [,2] [,3] [,4]
[1,] 25 72 23 55
[2,] 34 53 41 33
[3,] 26 43 26 44
[4,] 36 64 64 22
[5,] 47 72 67 34
stu<-t.test(genes[,1:2],genes[,3:4])
> stu$p.value
[1] 0.4198002
i get 1 pvalue for the entire col1:col2 Vs col3:col4. I am trying to get 5 p values for the 5 rows i have.
I am trying to avoid a for loop coz my
2011 Sep 19
1
regression summary results pvalues and coefficients into a excel
Hi All,
I have run many regression analyses (14000 +) and want to collect the
coefficients and pvalues into an excel file. I can get the statements below
to work up to step 4. I can printout the regressionresults (sample output
below).
So my hope is to run something like step 5 and 6 and put the pvalues (and
then coefficients) into an excel file. Can anyone suggest what I am doing
wrong or a
2011 Jul 05
0
function to compute pvalue for comparing two ROC curves
hi,
I'm looking to compare two area under ROC values for different classifiers
on the same data -- is there an r function to do this? Thanks!
[[alternative HTML version deleted]]
2007 May 02
0
KS test pvalue estimation using mctest (library truncgof)
Hi,
I'm trying to evaluate a Monte Carlo p-value (using truncgof package) on
a left truncated sample.
>From an empirical sample I've estimated a generalized pareto
distribution parameters (xi, beta, threshold) (I've used fExtremes pkg).
I'm in doubt on what of the following command is the most appropriate:
Let:
x<-sample
t<-threshold
xt<-x[x>t]
xihat<-gpdFit(x,
2004 Oct 04
1
Could anyone tell me how to extract pvalue from "lm" fitting?
Dear R people,
I have a naive question: after fitting "lm" to a data, I can't extract
the pvalue corresponding to a specific covariate in a direct way.
Could anyone give me a hint?
Thank you very much.
Frank
2004 Dec 30
1
t-test pvalue
Hi all,
I have some t-test values, and I am trying to obtain the associated p-values.
Is 'pt' the right command? I wonder why 1) it returns different values for
x and -x, and 2) how to obtain a 2-sided p-value.
example [R version 2.0.1, WinXP]:
#if t=2.23 (df=10), the expected p-value is 0.05 for 2-sided and 0.025 for
1-sided t-test
pt (2.23,10)
[1] 0.9750788
pt (-2.23,10) #or pt
2012 Oct 31
0
combined dependent pvalue
Dear All,
I am trying to combine dependent p-values in R. May you please help me with
this?
For independent pvalue combination, one of the popular way is fisher's
method which I found the R code here
(http://r.789695.n4.nabble.com/fisher-s-posthock-test-or-fisher-s-combination-test-td2195964.html#a2305025):
fisher.comb <- function (pvalues)
{
df=length(pvalues)
2023 Oct 29
1
The argument 'eps.Pvalue' of `printCoefmat()`
Hi all,
Just a minor issue that I am not sure whether this is considered a
"bug." It is about the help page.
In the help page of printCoefmat(), for the argument 'eps.Pvalue', the
description is as below:
number, ..
I have to read the source to figure out that this argument is to be
used by format.pval().
Maybe the description of 'eps.Pvalue' can be revised to refer
2023 Oct 29
1
The argument 'eps.Pvalue' of `printCoefmat()`
On 29/10/2023 3:48 a.m., Shu Fai Cheung wrote:
> Hi all,
>
> Just a minor issue that I am not sure whether this is considered a
> "bug." It is about the help page.
>
> In the help page of printCoefmat(), for the argument 'eps.Pvalue', the
> description is as below:
>
> number, ..
>
> I have to read the source to figure out that this argument
2003 Dec 18
1
bootstrap pValue in DClusters
Hello R-List
I use DClusters package (I work in a cancer regestry). I have 2 questions
about it:
1-how is it possible to get back the bootstrap pValue? I mean the pValue of
the calculated statistic with respect of the distribution of this statistic
under the null hypothesis.
2-how is it possible to test an overdispersion in the poisson model? for
choosing a best model I need this mesure of