Displaying 20 results from an estimated 200 matches similar to: "cvTools for 2 models not working"
2018 Apr 25
0
Zero errors : Bug in my R code ?
Dear R-experts,
I guess I have a problem with my fast function (fast tau estimator) here below. Indeed, zero errors look highly suspicious. I guess there is a bug in my R code. How could I correct my R code ?
# install.packages( "robustbase" )
# install.packages( "MASS" )
# install.packages( "quantreg" )
# install.packages( "RobPer" )
#
2018 Apr 21
0
Cross-validation : can't get the predicted response on the testing data
Dear R-experts,
Doing cross-validation for 2 robust regressions (HBR and fast Tau). I can't get the 2 errors rates (RMSE and MAPE). The problem is to predict the response on the testing data. I get 2 error messages.
Here below the reproducible (fictional example) R code.
#install.packages("MLmetrics")
# install.packages( "robustbase" )
# install.packages(
2018 May 08
0
Average of results coming from B=100 repetitions (looping)
On 5/8/2018 12:26 PM, varin sacha via R-help wrote:
>
> Dear R-experts,
>
> Here below the reproducible example. I am trying to get the average of the 100 results coming from the "lst" function. I have tried lst$mean and mean(lst). It does not work.
> Any help would be highly appreciated >
> ####################
>
> ?## R script for getting MedAe and
2018 May 08
4
Average of results coming from B=100 repetitions (looping)
Dear R-experts,
Here below the reproducible example. I am trying to get the average of the 100 results coming from the "lst" function. I have tried lst$mean and mean(lst). It does not work.
Any help would be highly appreciated.
####################
?## R script for getting MedAe and MedAeSQ from HBR model on Testing data
install.packages("robustbase")
install.packages(
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 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)
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
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
2009 Aug 12
1
psi not functioning in nlrob?
Hi all,
I'm trying to fit a nonlinear regression by "nlrob":
model3=nlrob(y~a1*x^a2,data=transient,psi=psi.bisquare,
start=list(a1=0.02,a2=0.7),maxit=1000)
However an error message keeps popping up saying that the function
psi.bisquare doesn't exist.
I also tried psi.huber, which is supposed to be the default for nlrob:
model3=nlrob(y~a1*x^a2,data=transient,psi=psi.huber,
2010 Jan 21
3
cross validation function translated from stata
Hi, everyone:
I ask for help about translating a stata program into R.
The program perform cross validation as it stated.
#1. Randomly divide the data set into 10 sets of equal size, ensuring equal
numbers of events in each set
#2. Fit the model leaving out the 1st set
#3. Apply the fitted model in (2) to the 1st set to obtain the predicted
probability of a prostate cancer diagnosis.
#4. Repeat
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
2011 Dec 19
2
nlrob problem
Dear all,
I am not sure if this mail is for R-help or should be sent to R-devel
instead, and therefore post to both.
While using nlrob from package 'robustbase', I ran into the following
problem:
For psi-functions that can become zero (e.g. psi.bisquare), weights in
the internal call to nls can become zero. Example:
d <- data.frame(x=1:5,y=c(2,3,5,10,9))
d.nlrob <-
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
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.
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
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
2006 Mar 30
0
Robust measures of goodness of fit?
Dear all,
I have been using rlm() for robust regression. Could someone please
suggest an appropriate measure of goodness-of-fit [1]? All I've found
after trawling the web, literature databases, and previous r-help posts,
is the "robust R^2" on pp. 362-363 of the S-plus manual, which is
available at
http://web.mit.edu/afs/athena/software/splus_v7.0/www/statman1.pdf
(7.57 MB)
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 <-
2011 Jun 20
2
Error of Cross Validation
Dear R users:
Recently, I tried to write a program to calculate cross-validated predicted
value.
My sources are as follows. However, the R reported an error.
Could you please check the sources? Thanks.
set.seed(100)
x<-rnorm(100)
y<-sample(rep(0:1,50),replace=T)
dat<-data.frame(x,y)
library(rms)
fito<-lrm(y~x)
preo<-predict(fito)
pre<-matrix(NA,nrow=100,ncol=200)
for (i in