Displaying 20 results from an estimated 1000 matches similar to: "Weighted Likelihood Estimation of NIG Dist."
2011 Jan 13
1
Weighted Optimization
Hi All,
I am trying to code an R script which gives me the time varying parameters of the NIG and GH distributions. Further, becasue I think these these time varying parameters should be more responsive to more recent observations, I would like to include a weighted likelihood estimation proceedure where the observations have an exponentially decaying weighting rather than the equal weighting
2006 Jan 23
1
weighted likelihood for lme
Dear R users,
I'm trying to fit a simple random intercept model with a fixed intercept.
Suppose I want to assign a weight w_i to the i-th contribute to the log-likelihood, i.e.
w_i * logLik_i
where logLik_i is the log-likelihood for the i-th subject.
I want to maximize the likelihood for N subjects
Sum_i {w_i * logLik_i}
Here is a simple example to reproduce
2004 Dec 22
0
weighted kernel density estimation
Dear wizaRds,
I use the MASS::kde2d function to estimate density of the two first
principal components. I do that to have a graphic visualisation of a
"group structure" in my dataset. So far, no problem.
But i would like to estimate that density using weights according to the
COS?? values that tells me if my observation is well represented on the
factorial plan 1-2. I would like to
2017 Dec 03
1
Discourage the weights= option of lm with summarized data
Peter,
This is a highly structured text. Just for the discussion, I separate
the building blocks, where (D) and (E) and (F) are new:
BEGIN OF TEXT --------------------
(A)
Non-?NULL? ?weights? can be used to indicate that different
observations have different variances (with the values in ?weights?
being inversely proportional to the variances);
(B)
or equivalently, when the elements of
2003 Sep 03
0
Matrix problem - possibly use of 'outer'
Hi,
I can't get my head around this - can someone give me a pointer:
I have a vector of values ('orig') representing areas and I want to
calculate the amount contributed by each original vector values in a
new vector ('new'). I find this hard to explain so here is a graphical
explanation:
# CODE START
orig <- 10:1 #10 values with varying area
new <-
2003 Dec 15
1
distribution of second order statistic
Hi,
I am getting some weird results here and I think I am missing something.
I am trying to program a function that for a set of random variables
drawn from uniform distributions plots that distribution of the second
order statistic of the ordered variables. (ie I have n uniform
distributions on [0, w_i] for w_i different w_j and i=1..n. I want to
plot the distribution of the second order
2010 Oct 27
1
GLM and Weights
Dear all,
I am trying to use the 'glm' package as part of a semiparametric technique that involves weighting a likelihood in various ways, i.e.
L(theta;data)=Sum_i=1,..,n (W_i)(log L(theta;data_i))
Where W_i can be a kernel weighting function, or W_i can be an indicator of 'non-missingness' divided by a propensity score.
In a Monte Carlo exercise, the option glm(...,
2017 Aug 18
1
Meta-regression of categorical variables
Dear metafor users,
I am working on a meta-analysis of reliability and the correlation associations.
I need some help about conducting categorical moderators variables.
Questions 1: How to conduct the weighted ANOVAs assuming a mixed-effects model on the tranformed alpha coefficients/the tranformes correlation coefficients for the categorical moderator variables?
Questions 2: How to
2004 Dec 15
2
how to fit a weighted logistic regression?
I tried lrm in library(Design) but there is always
some error message. Is this function really doing the
weighted logistic regression as maximizing the
following likelihood:
\sum w_i*(y_i*\beta*x_i-log(1+exp(\beta*x_i)))
Does anybody know a better way to fit this kind of
model in R?
FYI: one example of getting error message is like:
> x=runif(10,0,3)
> y=c(rep(0,5),rep(1,5))
>
2017 Jun 26
0
Classic fail-safe N
I would suggest to post this to the (recently created) R-sig-meta-analysis mailing list. See:
https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis
Best,
Wolfgang
>-----Original Message-----
>From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Naike Wang
>Sent: Monday, June 26, 2017 08:32
>To: R-help at r-project.org
>Subject: [R] Classic fail-safe N
>
2017 Jun 26
2
Classic fail-safe N
Hi all,
I was conducting a meta-analysis of single proportions(i.e. without a
control group) using the metafor package. When I performed a classic
fail-safe N, I noticed that the result (the number of missing studies that
would bring p-value to the alpha, to be exact)was different than that I got
in Comprehensive Meta-Analysis Version 2.0. I wonder why R and CMA got
different results.
*Below is
2009 Dec 04
1
z to r transformation within print.rma.uni and forest from the package metafor
Dear R community,
I'm using the ,metafor'-package by Wolfgang Viechtbauer (Version: 0.5-5) to
calculate random-effects meta-analyses using Correlations and Sample Sizes
as the raw data.
(By the way: Really a nice piece of work, Wolfgang! Thanks heaps.)
I specified the "rma.uni' function so that it looks like this:
MAergebnis<-rma.uni(ri=PosOutc, ni=N,
2017 Jun 25
0
Classic fail-safe N
Hi all,
I was conducting a meta-analysis of single proportions(i.e. without a
control group) using the metafor package. When I performed a classic
fail-safe N, I noticed that the result (the number of missing studies that
would bring p-value to the alpha, to be exact)was different than that I got
in Comprehensive Meta-Analysis Version 2.0. I wonder why R and CMA got
different results.
*Below is
2007 Jun 28
0
maximum difference between two ECDF's
Hello,
I have a vector of samples x of length N. Associated with each
sample x_i is a certain weight w_i. All the weights are in another
vector w of the same length N.
I have another vector of samples y of length n (small n). All
these samples have equal weights 1/n. The ECDF of these samples
is defined as for example at
http://en.wikipedia.org/wiki/Empirical_distribution_function and
I can
2013 Jul 02
0
Optimización MINLP
Muy buenas,
Tengo la siguiente duda/problema,
He optimizado con éxito un problema de este tipo:
\sum f(x_i)
donde f es una curva exponencial (función no lineal)
sujeto a:
a_i < x_i < b_i
y
\sum f(x_i) < Presupuesto
Vamos, es repartir un presupuesto forzando a que inviertas como poco a_i y
como mucho b_i para cada i
Esto lo hecho correctamente usando el paquete:
2017 Nov 28
0
Discourage the weights= option of lm with summarized data
My local R-devel version now has (in ?lm)
Non-?NULL? ?weights? can be used to indicate that different
observations have different variances (with the values in
?weights? being inversely proportional to the variances); or
equivalently, when the elements of ?weights? are positive integers
w_i, that each response y_i is the mean of w_i unit-weight
observations
2014 Oct 08
2
Optimización con restricciones lineales
Hola a todos,
Estoy intentando resolver un problema de optimización con R con
restricciones lineales, pero no consigo incluir dichas restricciones. Es
decir,
f<-function(w){
sd(...) # desviación típica de ciertos datos
}
optim(rep(1/2,8),fn = f,lower=0,upper=1,method='L-BFGS-B') # no se como
incluir aquí las restricciones
Las restricciones son: la suma de los w_i es 1 y todos los
2012 May 05
3
metafor
Dear users of metafor,
I am working on a meta-analysis using the metafor package. I have a
excel csv database that I am working with. I am interested in pooling
the effect measures for a particular subgroup (European women) in this
csv database. I am conducting both sub-group and meta-regression.
In subgroup-analyses, I have stratified the database to create a
separate csv file just for European
2006 Apr 22
1
Partially crossed and nested random factors in lme/lmer
Hi all,
I am not a very proficient R-user yet, so I hope I am not wasting people?s
time. I want to run a linear mixed model with 3 random factors (A, B, C)
where A and B are partially crossed and C is nested within B. I understand
that this is not easily possible using lme but it might be using lmer. I
encountered two problems when trying:
Firstly, I can enter two random factors in lmer but
2005 Jul 06
1
Fichier supprim és entre temps
Bonjour,
J'ai un petit souci avec mon petit couple rsync over ssh. Quand je fais un
rsync d'une machine, et que celle-ci dispose d'une messagerie de type
vpopmail, le backup m'indique ? la fin que certains fichiers n'ont pu ?tre
transf?r?s. Ceci est du au fait que sachant que les services POP/SMTP sont
actif, des fichiers ont ?t? supprim?s entre le temps ou la liste des