Displaying 20 results from an estimated 700 matches similar to: "loess' robustness weights in loess"
2002 Mar 29
1
help with lme function
Hi all,
I have some difficulties with the lme function and so this is my problem.
Supoose i have the following model
y_(ijk)=beta_j + e_i + epsilon_(ijk)
where beta_j are fixed effects, e_i is a random effect and
epsilon_(ijk) is the error.
If i want to estimate a such model, i execute
>lme(y~vec.J , random~1 |vec .I )
where y is the vector of my data, vec.J is a factor object
2006 Nov 21
3
Fitting mixed-effects models with lme with fixed error term variances
Dear R users,
I am writing to you because I have a few question on how to fix
the error term variances in lme in the hope that you could help me. To
my knowledge, the closest possibility is to fix the var-cov structure,
but not the whole var-cov matrix. I found an old thread (a few years
ago) about this, and it seems that the only alternative is to write the
likelihood down and use optim or a
2003 Mar 29
1
Goodness of fit tests
I have a dataset which I want to model using a Poisson distribution, with a given parameter. I would like to know what is the proper way to do a ''goodness of fit'' test using R.
I know the steps I''d take if I were to do it ''manually'': grouping the numbers into classes, calculating the expected frequencies using ''ppois'', then
2003 Oct 23
1
Variance-covariance matrix for beta hat and b hat from lme
Dear all,
Given a LME model (following the notation of Pinheiro and Bates 2000) y_i
= X_i*beta + Z_i*b_i + e_i, is it possible to extract the
variance-covariance matrix for the estimated beta_i hat and b_i hat from the
lme fitted object?
The reason for needing this is because I want to have interval prediction on
the predicted values (at level = 0:1). The "predict.lme" seems to
2010 Jun 01
1
BreastCancer Dataset for Classification in kknn
Dear All,
I'm getting a error while trying to apply the BreastCancer dataset
(package=mlbench) to kknn (package=kknn) that I don't understand as I'm new
to R.
The codes are as follow:
rm = (list = ls())
library(mlbench)
data(BreastCancer)
library(kknn)
BCancer = na.omit(BreastCancer)
d = dim(BCancer)[1]
i1 = seq(1, d, 2)
i2 = seq(2, d, 2)
t1 = BCancer[i1, ]
t2 =
2006 Feb 10
1
Lmer with weights
Hello!
I would like to use lmer() to fit data, which are some estimates and
their standard errors i.e kind of a "meta" analysis. I wonder if weights
argument is the right one to use to include uncertainty (standard
errors) of "data" into the model. I would like to use lmer(), since I
would like to have a "freedom" in modeling, if this is at all possible.
For
2010 Feb 05
3
metafor package: effect sizes are not fully independent
In a classical meta analysis model y_i = X_i * beta_i + e_i, data
{y_i} are assumed to be independent effect sizes. However, I'm
encountering the following two scenarios:
(1) Each source has multiple effect sizes, thus {y_i} are not fully
independent with each other.
(2) Each source has multiple effect sizes, each of the effect size
from a source can be categorized as one of a factor levels
2005 Oct 18
2
Installing Bioconductor on R
hi all,
Am new to R. I am having problems installing Bioconductor package in
R on fedora core 4 running on AMD64 bit machine.
this is the error message I get :
gcc -shared -L/usr/local/lib -o affyPLM.so avg_log.o biweight.o
chipbackground.o common_types.o do_PLMrlm.o do_PLMrma.o do_PLMthreestep.o
idealmismatch.o LESN.o lm.o lm_threestep.o log_avg.o matrix_functions.o
2009 Aug 24
1
transforming data glm
Dear sir,
I am fitting a glm with default identity link:
model<-glm(timetoacceptsecs~maleage*maletub*relweight*malemobtrue*femmobtrue)
the model is overdisperesed and plot model shows a low level of linearity of the residuals. The overdispersion and linearity of residulas on the normal Q-Q plot is corrected well by using:
2004 Apr 29
3
Dummies in R
Dear all,
my problem is following. I know Stata, but currently I have to use R. Could You please help in finding the analogy to R.
(1) creating of City-Dummy.
I know in Stata:
g byte city=0
replace city=1 if city==12&year==2000
and
(2) Create a Time-Dummy-Variable
g byte T2000=0
replace T2000=1 if year==2000
(3) I need the City DUmmy for the following combination: I have the
1999 Dec 01
1
density(kernel = "cosine") .. the `wrong cosine' ..
I'm in teaching mode, kernel densities.
{History: density() was newly introduced in version 0.15, 19 Dec 1996;
most probably by Ross or Robert
}
When I was telling the students about different kernels (and why their
choice is not so important, and "equivalent bandwidths" etc,etc)
I wondered about the "Cosine" in my teaching notes which
is defined there as
k(x)
2005 Mar 28
1
mixed model question
I am trying to fit a linear mixed model of the form
y_ij = X_ij \beta + delta_i + e_ij
where e_ij ~N(0,s^2_ij) with s_ij known
and delta_i~N(0,tau^2)
I looked at the ecme routine in package:pan, but this routine
does not allow for different Vi (variance covariance matrix of
the e_i vector) matrices for each cluster.
Is there an easy way to fit this model in R or should I bite the
bullet and
2010 Dec 26
1
Calculation of BIC done by leaps-package
Hi Folks,
I've got a question concerning the calculation of the Schwarz-Criterion
(BIC) done by summary.regsubsets() of the leaps-package:
Using regsubsets() to perform subset-selection I receive an regsubsets
object that can be summarized by summary.regsubsets(). After this
operation the resulting summary contains a vector of BIC-values
representing models of size i=1,...,K.
My problem
2008 Feb 25
1
r44608 fails make check-all in scatter.smooth example
Dear List,
Having had my appetite sufficiently whetted by Prof. Ripley's email
about the new graphics capabilities in Unixes, I wanted to try them out.
I updated to svn r44608, configured with the following options:
R is now configured for x86_64-unknown-linux-gnu
Source directory: ..
Installation directory: /usr/local
C compiler: gcc -O3 -g -std=gnu99
2007 Jun 14
0
random effects in logistic regression (lmer)-- identification question
Hello R users!
I've been experimenting with lmer to estimate a mixed model with a
dichotomous dependent variable. The goal is to fit a hierarchical
model in which we compare the effect of individual and city-level
variables. I've run up against a conceptual problem that I expect one
of you can clear up for me.
The question is about random effects in the context of a model fit
with a
2010 Oct 19
3
scatter.smooth() fitted by loess
Hi there,
I would like to draw a scatter plot and fit a smooth line by loess.
Below is the data.
However, the curve line started from 0, which my "resid" list doesn't
consist of 0 value.
It returned some warnings which I don't know if this is the reason
affecting such problem. Here I also attached the warning messages.
Please let me know if there is a solution to fix this. Thank
2008 Jul 31
1
clustering and data-mining...
Hi all,
I am doing some experiment studies...
It seems to me that with different combination of 5 parameters, the end
results ultimately converged to two scalars. That's to say, some
combinations of the 5 parameters lead to one end result and some other
combinations of the 5 parameters lead to the other end result (scalar).
I am thinking of this is sort of something like clustering or
2005 Jul 12
1
getting panel.loess to use updated version of loess.smooth
I'm updating the loess routines to allow for, among other things,
arbitrary local polynomial degree and number of predictors. For now,
I've given the updated package its own namespace. The trouble is,
panel.loess still calls the original code in package:stats instead of
the new loess package, regardless of whether package:loess or
package:lattice comes first in the search list. If I
2008 Apr 04
2
predict.glm & newdata
Hi all -
I'm stumped by the following
mdl <- glm(resp ~ . , data = df, family=binomial, offset = ofst) WORKS
yhat <- predict(mdl) WORKS
yhat <- predict(mdl,newdata = df) FAILS
Error in drop(X[, piv, drop = FALSE] %*% beta[piv]) :
subscript out of bounds
I've tried without offset, quoting binomial. The offset variable ofst IS in df.
Previous postings indicate possible
2009 Sep 24
0
basic cubic spline smoothing (resending because not sure about pending)
Hello, I come from a non statistics background, but R is available to me,
and I needed to test an implementation of smoothing spline that I have
written in c++, so I would like to match the results with R (for my unit
tests).
I am following Smoothing Splines, D.G. Pollock (available online)
where we have a list of points (xi, yi), the yi points are random such that:
y_i = f(x_i) + e_i