Displaying 20 results from an estimated 7000 matches similar to: "weighted m-estimator"
2008 Nov 19
1
How to get robust M-estimator of multivariate scatter using Huber's psi?
How to get robust M-estimators of multivariate scatter using Huber's psi?
Which package/function should I look into? Ideally, I hope I can
self-define thresholds of Huber's psi function.
Thanks a lot!!!
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2004 Jul 05
2
nonlinear regression with M estimation
Hi All,
Could any one tells me if R or S has the capacity to fit nonlinear
regression with Huber's M estimation? Any suggestion is appreciated. I was
aware of 'rlm' in MASS library for robust linear regression and 'nls' for
nonlinear least squares regression, but did not seem to be able to find
robust non-linear regression function.
Thanks and regards,
Ray Liu
2018 Apr 06
1
Fast tau-estimator line does not appear on the plot
R-experts,
I have fitted many different lines. The fast-tau estimator (yellow line) seems strange to me?because this yellow line is not at all in agreement with the other lines (reverse slope, I mean the yellow line has a positive slope and the other ones have negative slope).
Is there something wrong in my R code ? Is it because the Y variable is 1 vector and should be a matrix ?
Here is the
2012 Nov 22
1
help in M-estimator by R
hi guys and gals ... How are you all ...
i have to do something in robust regression by R programm , and i have some
problems as following:
*the first :*
suppose
w(r) =1/(1 r^2) and r <- c(7.01,2.07,7.061,5.607,8.502,54.909,12.222)
and i want to exclude some values from r so that (abs(r)>4.9 )...
after ,i want to used (w) to get on coefficients beta0 and beta1 (B1 <-
2018 Apr 07
0
Fast tau-estimator line does not appear on the plot
You need to pay attention to the documentation more closely. If you don't
know what something means, that is usually a signal that you need to study
more... in this case about the difference between an input variable and a
design (model) matrix. This is a concept from the standard linear algebra
formulation for regression equations. (Note that I have never used RobPer,
nor do I regularly
2018 Mar 31
0
Fast tau-estimator line does ot appear on the plot
On 31/03/2018 11:57 AM, varin sacha via R-help wrote:
> Dear R-experts,
>
> Here below my reproducible R code. I want to add many straight lines to a plot using "abline"
> The last fit (fast Tau-estimator, color yellow) will not appear on the plot. What is going wrong ?
> Many thanks for your reply.
>
It's not quite reproducible: you forgot the line to create
2018 Mar 31
2
Fast tau-estimator line does ot appear on the plot
Dear R-experts,
Here below my reproducible R code. I want to add many straight lines to a plot using "abline"
The last fit (fast Tau-estimator, color yellow) will not appear on the plot. What is going wrong ?
Many thanks for your reply.
##########
Y=c(2,4,5,4,3,4,2,3,56,5,4,3,4,5,6,5,4,5,34,21,12,13,12,8,9,7,43,12,19,21)
2005 Aug 23
1
Robust M-Estimator Comparison
Hello,
I'm learning about robust M-estimators right now and had settled on the
"Huber Proposal 2" as implemented in MASS, but further reading made clear,
that at least 2 further weighting functions (Hampel, Tukey bisquare) exist.
In a post from B.D. Ripley going back to 1999 I found the following quote:
>> 2) Would huber() give me results that are similar (i.e., close
2008 May 02
2
my first post to the list
Hello R-listers! My first post to the list is a very simple one for those
who use the software continuosly. I am trying to understand the fixed-x
resampling and random-x-resampling method proposed by Fox about
Bootstrapping. The doubt that I have is on the side of the model run in one
of the functions expressed for fixed-x resampling. What I don't understand
is: X=model.matrix, and the -1
2005 Dec 22
1
Huber location estimate
We have a choice when calculating the Huber location estimate:
> set.seed(221205)
> y <- 7 + 3*rt(30,1)
> library(MASS)
> huber(y)$mu
[1] 5.9117
> coefficients(rlm(y~1))
(Intercept)
5.9204
I was surprised to get two different results. The function huber() works
directly with the definition whereas rlm() uses iteratively reweighted
least squares.
My surprise is
2000 Dec 12
1
[Fwd: R code and robust regression]
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2010 Aug 06
3
m-estimators
Dear colleagues
can somebody help me by showing how we can compute m-estimators in R?
thanks
Dr. Iasonas Lamprianou
Assistant Professor (Educational Research and Evaluation)
Department of Education Sciences
European University-Cyprus
P.O. Box 22006
1516 Nicosia
Cyprus
Tel.: +357-22-713178
Fax: +357-22-590539
Honorary Research Fellow
Department of Education
The University of Manchester
1999 Sep 17
1
Tukey's biweight
I want to estimate the center of a distribution with lots of outliers in one
tail, and thought I would use a function such as S-plus's location.m() with
psi.fun=bisquare (as per MASS 3 p. 131). However, R seems not have such a
function, so my questions are:
1) Is there an R equivalent to location.m()?
2) Would huber() give me results that are similar (i.e., close enough)?
Thanks.
2001 Aug 23
1
location.m in R?
Hi.
I'm looking for the robust M estimates comparable to "location.m" in
S-PLUS?
Alternatively, I guess I could use
> lqs(x~1)
But ... is "location.m" in a package?
Thanks,
M.
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r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info",
2007 Nov 21
1
equivalent of Matlab robustfit?
Hi,
I've been using the Matlab robustfit function for linear regressions
where I suspect some data points are outliers. Is there an equivalent
function in R?
Take care, Darren
PS, This is the Matlab help on robustfit:
>> help robustfit
ROBUSTFIT Robust linear regression
B = ROBUSTFIT(X,Y) returns the vector B of regression coefficients,
obtained by performing robust
2011 Feb 28
1
Robust variance estimation with rq (failure of the bootstrap?)
I am fitting quantile regression models using data collected from a
sample of 124 patients. When modeling cross-sectional associations, I
have noticed that nonparametric bootstrap estimates of the variances
of parameter estimates are much greater in magnitude than the
empirical Huber estimates derived using summary.rq's "nid" option.
The outcome variable is severely skewed, and I am
2014 Oct 05
0
Bug#764113: Bug#764113: xen: build-dependency on libgnutls-dev
Control: reassign -1 libgnutls-dev
On Sun, Oct 05, 2014 at 03:57:50PM +0200, Andreas Metzler wrote:
> xen build-depends on libgnutls-dev which is
> - scheduled for removal
> - and (somehow related) uninstallable.
Nice, but this is not a problem in xen but in libgnutls-dev.
Re-assigning.
Basian
--
Death, when unnecessary, is a tragic thing.
-- Flint, "Requiem for
2011 Feb 03
1
"hubers" function in R MASS library : problem and solution
Hello:
I found the "hubers" function in MASS library is NOT working on the following
data:
> a <-
2010 Jan 16
1
"Too many raster images" in devPS.c
Hi,
I am finding the recently added [1] functionality of embedding raster
images into plots on R devices very useful! Thanks to Paul Murrell and
others for providing that. I noted that in
https://svn.r-project.org/R/trunk/src/library/grDevices/src/devPS.c
a macro is defined: #define MAX_RASTERS 64, and consequently, I get
Error in grid.Call.graphics("L_raster", x$raster, x$x, x$y,
2018 Sep 20
2
A different error in sample()
FWIW, I suspect this is related to the function R_unif_index that was
introduced in src/main/RNG.c around revision 72356, or the way this
function is used in do_sample in src/main/random.c.
20.9.18 08:19, Wolfgang Huber scripsit:
> Besides wording of the documentation re truncating vs rounding, there is
> something peculiar going on with the fractional part of n:
>
> >