Displaying 20 results from an estimated 4000 matches similar to: "New psi with rlm"
2006 Feb 10
1
precision of std. error in summary
Hi,
I'm doing robust regression with the following command
rlm(dip~ind1+ind2-1,method="M",psi=psi,maxit=1000,acc=1e-15)
now when I ask for a summary
summary(rlm(dip~ind1+ind2-1,method="M",psi=psi,maxit=1000,acc=1e-15))
I get
Coefficients:
Value Std. Error t value
ind1 -0.0377 0.0000 -24203.1415
ind2 1.0370 0.0000 668735.7195
taht is
2005 Feb 05
2
Std Err on Concentration measures
Hi,
I'm using the ineq package to calculate some concentration measures (Gini, Herfindal, ...) and I was wondering if there's around also a function to calculate standard error on these measures. If not, is anybody aware of where I can find a reference on this point?
Thanks.
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Angelo Secchi PGP Key ID:EA280337
2006 Feb 08
3
rob var/cov + LAD regression
Hi,
after looking around I was not able to get info about these two questions:
1. Is there a function to have a "jackknifed corrected var/cov estimate" (as described in MacKinnon and White 1985) in a standard OLS regression?
2. Does R possess a LAD (Least Absolute Deviation) regression function?
Any help?
Thanks
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Angelo
2005 Nov 07
1
Newbie on functions
Hi,
I'm trying to write a simple function like
case1 <- function (m, cov, Q, R) {
theta <- (acos(R/sqrt(Q^3)))
beta <- (-2)*sqrt(Q)*cos(theta/3)+m[1]/3
rho1 <- (-2)*sqrt(Q)*cos((theta+2*pi)/3)+m[1]/3
rho2 <- (-2)*sqrt(Q)*cos((theta-2*pi)/3)+m[1]/3
stderrb <- deltamethod( ~(-2)*sqrt(Q)*cos(theta/3)+x1/3,m,cov)
stderrr1 <- deltamethod(
2008 Jan 19
1
How do we get two-tailed p-values for rlm?
How do we get 2-tailed p-values for the rlm summary?
I'm using the following:
> fit <- rlm(oatRT ~ oatoacData$erp, psi=psi.bisquare, maxit=100,
na.action='na.omit')
> fitsum <- summary(fit, cor=F)
> print(fitsum)
Call: rlm(formula = oatRT ~ oatoacData$erp, psi = psi.bisquare, maxit = 100,
na.action = "na.omit")
Residuals:
Min 1Q Median
2005 Mar 24
1
Robust multivariate regression with rlm
Dear Group,
I am having trouble with using rlm on multivariate data sets. When I
call rlm I get
Error in lm.wfit(x, y, w, method = "qr") :
incompatible dimensions
lm on the same data sets seem to work well (see code example). Am I
doing something wrong?
I have already browsed through the forums and google but could not find
any related discussions.
I use Windows XP and R
2004 Oct 11
3
split and rlm
Hello, I'm trying to do a little rlm of some data that looks like this:
UNIT COHORT perdo adjodds
1010 96 0.39890 1.06894
1010 97 0.48113 1.57500
1010 98 0.36328 1.21498
1010 99 0.44391 1.38608
It works fine like this: rlm(perdo ~ COHORT, psi=psisquare)
But the problem is that I have about 100 UNITs, and I want to do a
2005 Mar 18
3
Non linear modeling
AFAIK most model fitting techniques will only deal with additive errors, not
multiplicative ones. You might want to try fitting:
log(y-x) = a*x + e
which is linear.
Andy
> From: Angelo Secchi
>
> Hi,
> is there a way in R to fit a non linear model like
>
> y=x+exp(a*x)*eps
>
> where a is the parameter and eps is the error term?
> Thanks
> Angelo
>
>
2012 Jul 18
1
How does "rlm" in R decide its "w" weights for each IRLS iteration?
Hi all,
I am also confused about the manual:
a. The input arguments:
wt.method are the weights case weights (giving the relative importance of
case, so a weight of 2 means there are two of these) or the inverse of the
variances, so a weight of two means this error is half as variable?
w (optional) initial down-weighting for each case.
init (optional) initial values for the
2011 Mar 16
0
cross validation? when rlm, lmrob or lmRob
Dear community,
I have fitted a model using comands above, (rlm, lmrob or lmRob). I don't
have new data to validate de models obtained. I was wondering if exists
something similar to CVlm in robust regression. In case there isn't, any
suggestion for validation would be appreciated.
Thanks, user at host.com
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2018 Apr 13
0
cvTools for 2 models not working
Dear R-experts,
I am trying to do cross-validation for different models using the cvTools package.
I can't get the CV for the "FastTau" and "hbrfit". I guess I have to write my own functions at least for hbrfit. What is going wrong with FastTau ?
Here below the reproducible example. It is a simple toy example (not my real dataset) with many warnings, what is important to
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
2004 Aug 01
1
Problem with RGui and MASS
Hi,
Using R1.9.1 for Windows with Windows 2000 (also XP), I have come
across the following problem that I have not seen before and am at
a loss to explain. If I create an object using rlm from library(MASS)
and then save the workspace, I cannot reopen it using RGUI by double
clicking on the .RData file as I normally do. If I double click on
the icon, R starts and then gives the following
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
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)
2011 Mar 14
1
discrepancy between lm and MASS:rlm
Dear R-devel,
There seems to be a discrepancy in the order in which lm and rlm evaluate their arguments. This causes rlm to sometimes produce an error where lm is just fine.
Here is a little script that illustrate the issue:
> library(MASS)
> ## create data
> n <- 100
> dat <- data.frame(x=rep(c(-1,0,1), n), y=rnorm(3*n))
>
> ## call lm, works fine
> summary(lm(y ~
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
2012 Jul 06
1
How to do goodness-of-fit diagnosis and model checking for rlm in R?
Hi all,
I am reading the MASS book but it doesn't give examples about the diagnosis
and model checking for rlm...
My data is highly non-Gaussian so I am using rlm instead of lm.
My questions are:
0. Are goodness-of-fit and model-checking using rlm completely the same as
usual regression?
1.
Please give me some pointers about how to do goodness-of-fit and
residual diagnosis for
2010 Nov 08
1
Add values of rlm coefficients to xyplot
Hello,
I have a simple xyplot with rlm lines.
I would like to add the a and b coefficients (y=ax+b) of the rlm calculation
in each panel.
I know I can do it 'outside' the xyplot command but I would like to do all
at the same time.
I found some posts with the same question, but no answer.
Is it impossible ?
Thanks in advance for your help.
Ptit Bleu.
x11(15,12)
xyplot(df1$col2 ~