Displaying 20 results from an estimated 130 matches similar to: "How do we get two-tailed p-values for rlm?"
2004 Oct 27
1
writing lm summary to file?
Hi,
I want to write the summary from a regression. I am doing this because I do not see a way of get the std error, tvalues from the coefficients diagnostic. n$coef does not give this only get the intercept and slope. I tried to use write and write.table and got error in both cases. I jumped thru the hoops below to no avail. Also note, this is in windows. I used to use unix, and do not
2012 Nov 13
1
About systemfit package
Dear friends,
I have written the following lines in R console wich already exist in pdf
file systemfit:
data( "GrunfeldGreene" )
library( "plm" )
GGPanel <- plm.data( GrunfeldGreene, c( "firm", "year" ) )
greeneSur <- systemfit( invest ~ value + capital, method = "SUR",
+ data = GGPanel )
greenSur
I have obtained the following incomplete
2011 Aug 23
1
P values for vglm(zibinomial) function in VGAM
Hi ,
I know this question has been asked twice in the past but to my knowldege,
it still hasn't been solved.
I am doing a zero inflated binomial model using the VGAM package, I need to
obtain p values for my Tvalues in the vglm output. code is as follows
> mod2=vglm(dmat~Season+Diel+Tidal.phase+Tidal.cycle,zibinomial, data=mp1)
> summary(mod2)
Call:
vglm(formula = dmat ~ Season +
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
--
View this message in context:
2011 Apr 18
0
apply lm.beta() to rlm object (robust regression)
Hello,
I'm trying to do a regression analysis (multiple linear regression) and have
to deal with a slight heteroscedascitiy in my data.
I've read somewhere that it's possible to use the rlm (robust regression)
out of the MASS package in such cases. Is it possible to apply the lm.beta
method (from package QuantPsyc) to the returned rlm object and/or is there a
way to calculate
2005 Mar 27
1
p values when using rlm
R 2.0.1
Linux
I am using rlm() to fit a model, e.g. fit1<-rlm(y~x). My model is more
complex than the one shown.
When I enter summary(fit1)
I get estimates for the model's coefficients along with their SEs, and
t values, but no p values. The p value column is blank.
Similarly, when I enter anova(fit1) I get DF, Sum Sq, Mean Sq, but the
column for F value and Pr(>F) are blank.
Any
2006 Feb 09
0
New psi with rlm
Hi,
How can I define a new psi function in the rlm comand?
In particular I would like to implement the case for
\rho(u)=0.5*(u^2) and \psi(u)=u
in order to assume normally distributed errors.
Any help?
Thanks
--
========================================================
Angelo Secchi PGP Key ID:EA280337
2007 Jun 07
3
rlm results on trellis plot
How do I add to a trellis plot the best fit line from a robust fit? I
can use panel.lm to add a least squares fit, but there is no panel.rlm
function.
--
Alan S Barnett <asb at mail.nih.gov>
NIMH/CBDB
2004 Apr 27
0
lmRobMM vs rlm
I am needing some expertise with regard
to the S-Plus command lmRobMM and its R counterpart
rlm(formula,data,method="MM")
I have used lmRobMM(formula,data) in S-Plus on the Stackloss data and
obtained for my residuals
6.217777 1.150717 6.427946 8.174019 -0.6713005 -1.248641 -0.4236203
0.5763797 -1.057899 0.3593823
11 12 13 14 15 16
2005 Sep 06
0
MASS: rlm, MM and errors in observations AND regressors
Hello,
I need to perform a robust regression on data which contains errors in BOTH
observations and regressors. Right now I am using rlm from the MASS package
with 'method="MM"' and get visually very nice results. MASS is quite clear,
however, that the described methodologies are only applicable to
observation-error only data (p. 157, 4th Ed.). So here's the questions now:
2008 May 14
1
rlm and lmrob error messages
Hello all,
I'm using R2.7.0 (on Windows 2000) and I'm trying do run a robust
regression on following model structure:
model = "Y ~ x1*x2 / (x3 + x4 + x5 +x6)"
where x1 and x2 are both factors (either 1 or 0) and x3.....x6 are numeric.
The error code I get when running rlm(as.formula(model), data=daymean) is:
error in rlm.default(x, y, weights, method = method, wt.method =
2010 Aug 17
0
Singular error in rlm
I am absolutely new to R and I am aware of only a few basic command lines. I
was running a robust regression in R, using the following command line
library (MASS)
rfmodel2 <- rlm (TotalEmployment_2005 ~ ALABAMA + MISSISSIPPI + LOUISIANA +
TotalEmployment_2000 + PCWhitePop_2005 + UnemploymentRate_2005 +
PCUrbanPop2000 + PCPeopleWithACollegeDegree_2000 +
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
2007 May 31
0
loading several "samples" of data from hard-drive, run "lm", "rlm", etc, save results in a list
I have many "sample" datasets (e.g. sample 5, sample 6, etc), each identified by a number as a suffix. These datasets are saved as individual R objects on my hard drive. (e.g."Wind.5.r" . "Wind.6.r","Solar.5.r","Solar.6.r") For example purposes, I have written code that creates similar data files using the "airquality" dataset. (see
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 ~
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
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
2009 Dec 03
2
Avoiding singular fits in rlm
I keep coming back to this problem of singular fits in rlm (MASS library),
but cannot figure out a good solution.
I am fitting a linear model with a factor variable, like
lm( Y ~ factorVar)
and this works fine. lm knows to construct the contrast matrix the way I
would expect, which puts the first factor as the baseline level.
But when I try
rlm( Y ~ factorVar)
I get the message "'x'
2008 Dec 08
1
residual standard error in rlm (MASS package)
Hi,
I would appreciate of someone could explain how the residual standard
error is computed for rlm models (MASS package). Usually, one would
expect to get the residual standard error by
> sqrt(sum((y-fitted(fm))^2)/(n-2))
where y is the response, fm a linear model with an intercept and slope
for x and n the number of observations. This does not seem to work for
rlm models and I am wondering
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 ~