Displaying 20 results from an estimated 100 matches similar to: "use of sequence on ridge regression"
2011 Feb 28
1
Creating new variables. How do you get them into a data frame?
Hi
I'm an R newbie. I can't seem to add new variables to data frames. Here are
the stages
(1) I import the data using read.csv.
(2) I fix it using fix(data)
(3) I create a new variable using
spos<-tagPOS(stim,language="en",model=NULL,tagdict=NULL).
(tagPOS is a function in the OpenNLP toolkit, which tags a string for part
of speech. "stim" is a variable in the
2005 Aug 24
1
lm.ridge
Hello, I have posted this mail a few days ago but I did it wrong, I hope
is right now:
I have the following doubts related with lm.ridge, from MASS package. To
show the problem using the Longley example, I have the following doubts:
First: I think coefficients from lm(Employed~.,data=longley) should be
equal coefficients from lm.ridge(Employed~.,data=longley, lambda=0) why
it does not happen?
2002 Nov 08
0
Polar plot, circular plot (angular data): II
Dear R-users,
As noted by Paul Murrell < p.murrell at auckland.ac.nz > there is errors in the code for polar plotting I send to R-help under the title "Polar plot, circular plot (angular data)" at Thu Oct 17 2002 - 12:18:20 CEST.
Thanks!
I have reorganized the code into a structure ('pp'). This allows plots to be modified to a greater extent by passing arguments by ...
2011 Aug 23
1
obtaining p-values for lm.ridge() coefficients (package 'MASS')
Dear all
I'm familiarising myself with Ridge Regressions in R and the following
is bugging me: How does one get p-values for the coefficients obtained
from MASS::lm.ridge() output (for a given lambda)? Consider the
example below (adapted from PRA [1]):
> require(MASS)
> data(longley)
> gr <- lm.ridge(Employed ~ .,longley,lambda = seq(0,0.1,0.001))
> plot(gr)
> select(gr)
2008 May 05
3
downloading packages at local disk
Hi again R users. I was reviewing the manual of R about how to install
packages using the GUI and it's corresponding menu packages. My
question is how to download a specific set of packages in order to
install them in a computer that doesn't have internet access. Is there
a web page where I can search those packages? Basically I'm trying to
copy in a flash drive the packages MASS, BOOT
2009 Jun 04
0
help needed with ridge regression and choice of lambda with lm.ridge!!!
Hi,
I'm a beginner in the field, I have to perform the ridge regression with lm.ridge for many datasets, and I wanted to do it in an automatic way.
In which way I can automatically choose lambda ?
As said, right now I'm using lm.ridge MASS function, which I found quite simple and fast, and I've seen that among the returned values there are HKB estimate of the ridge constant and L-W
2009 Mar 17
1
Likelihood of a ridge regression (lm.ridge)?
Dear all,
I want to get the likelihood (or AIC or BIC) of a ridge regression model
using lm.ridge from the MASS library. Yet, I can't really find it. As
lm.ridge does not return a standard fit object, it doesn't work with
functions like e.g. BIC (nlme package). Is there a way around it? I would
calculate it myself, but I'm not sure how to do that for a ridge regression.
Thank you in
2011 Aug 06
0
ridge regression - covariance matrices of ridge coefficients
For an application of ridge regression, I need to get the covariance
matrices of the estimated regression
coefficients in addition to the coefficients for all values of the ridge
contstant, lambda.
I've studied the code in MASS:::lm.ridge, but don't see how to do this
because the code is vectorized using
one svd calculation. The relevant lines from lm.ridge, using X, Y are:
2010 Feb 16
1
survival - ratio likelihood for ridge coxph()
It seems to me that R returns the unpenalized log-likelihood for the ratio likelihood test when ridge regression Cox proportional model is implemented. Is this as expected?
In the example below, if I am not mistaken, fit$loglik[2] is unpenalized log-likelihood for the final estimates of coefficients. I would expect to get the penalized log-likelihood. I would like to check if this is as expected.
2010 Dec 15
0
ridge() function and coxph
I need to add a belated acknowledgement to my prior comments. Thomas
Lumley has also been a significant contributer to the survival code.
Until I moved my development from Splus to R he was the primary
maintainer of the R code, he tightened up a lot of the C code to make
sure it would work on multiple architectures, and added several
functions. Merging our two code bases back together was a
2010 Dec 02
0
survival - summary and score test for ridge coxph()
It seems to me that summary for ridge coxph() prints summary but returns NULL. It is not a big issue because one can calculate statistics directly from a coxph.object. However, for some reason the score test is not calculated for ridge coxph(), i.e score nor rscore components are not included in the coxph object when ridge is specified. Please find the code below. I use 2.9.2 R with 2.35-4 version
2006 Nov 03
0
R package/function for ridge logistic regression
Hi,
Is there a R function/package which could do ridge regression for
logistic regression? Thank you.
--
Zheng
2008 Jan 28
0
[OT] - standard errors for parameter estimates under ridge regression and lasso?
Dear R community,
I'm curious to know how people go about estimating standard errors for
parameter estimates after model selection by ridge regression and the
lasso. Do you have any practical or theoretical advice?
Warmly,
Andrew
--
Andrew Robinson
Department of Mathematics and Statistics Tel: +61-3-8344-9763
University of Melbourne, VIC 3010 Australia Fax:
2010 Jun 08
0
About lm.ridge in the MASS package
Hi,
I had a questions about doing ridge regression in R.
Why is it that when I try this on datasets with more predictors than samples (p>n) using lambda=0, it still finds coefficients for all predictors? I thought when lambda=0, it should be like ordinary regression and therefore not find coefficients for all due to singularity?
I would greatly appreciate your help.
Thank you,
--James K.
2009 Aug 15
0
coefficient p-value in ridge regression
Hello. I'have a problem with RIDGE REGRESSION.
I've used lm.ridge function to estimate coefficients of my model. Why in the summary of models not appears t value, Pr(>|t|) and significance stars?
How I can calculate coefficient's p-value in ridge regression?
Thanks!
[[alternative HTML version deleted]]
2010 Jan 06
0
parcor 0.2-2 - Regularized Partial Correlation Matrices with (adaptive) Lasso, PLS, and Ridge Regression
Dear R-users,
we are happy to announce the release of our R package parcor.
The package contains tools to estimate the matrix of partial
correlations based on different regularized regression methods: Lasso,
adaptive Lasso, PLS, and Ridge Regression. In addition, parcor provides
cross-validation based model selection for Lasso, adaptive Lasso and
Ridge Regression.
More details can be found
2010 Jan 06
0
parcor 0.2-2 - Regularized Partial Correlation Matrices with (adaptive) Lasso, PLS, and Ridge Regression
Dear R-users,
we are happy to announce the release of our R package parcor.
The package contains tools to estimate the matrix of partial
correlations based on different regularized regression methods: Lasso,
adaptive Lasso, PLS, and Ridge Regression. In addition, parcor provides
cross-validation based model selection for Lasso, adaptive Lasso and
Ridge Regression.
More details can be found
2010 Apr 26
0
lm.ridge {MASS} intercept questions
I am trying to understand the code for lm.ridge from the MASS package.
Here is the part I am having trouble understanding:
if(Inter <- attr(Terms, "intercept"))
{
Xm <- colMeans(X[, -Inter])
Ym <- mean(Y)
p <- p - 1
X <- X[, -Inter] - rep(Xm, rep(n, p))
Y <- Y - Ym
} else Ym <- Xm <- NA
Xscale <- drop(rep(1/n, n) %*% X^2)^0.5
X <- X/rep(Xscale, rep.int(n,
2017 Oct 31
0
lasso and ridge regression
Dear All
The problem is about regularization methods in multiple regression when the
independent variables are collinear. A modified regularization method with
two tuning parameters l1 and l2 and their product l1*l2 (Lambda 1 and
Lambda 2) such that l1 takes care of ridge property and l2 takes care of
LASSO property is proposed
The proposed method is given
2013 Apr 16
1
[Ping:] [Patch] iso9660.c did not copy terminating 0 of Rock Ridge name
Hi,
i cannot yet see my most recent bug fix patch applied to
http://git.kernel.org/cgit/boot/syslinux/syslinux.git/log/?h=rockridge
The fixed problem could lead to memory faults.
http://www.syslinux.org/archives/2013-April/019790.html
Have a nice day :)
Thomas