[R] Ridge regression for beta and gamma models

2014-04-28 Thread john james
Dear All, Please, is there any package in R that has implemented ridge regression for beta and gamma models? If not, kindly help me to adjust my model below for the beta regression so as to accommodate ridge penalty. Thanks. lbeta <- function(par,y,X){ n <-length(y) k <- ncol(X) beta <- par[

[R] Ridge regression

2013-04-29 Thread Preetam Pal
Hi all, I have run a ridge regression on a data set 'final' as follows: reg=lm.ridge(final$l~final$lag1+final$lag2+final$g+final$u, lambda=seq(0,10,0.01)) Then I enter : select(reg) and it returns: modified HKB estimator is 19.3409 modified L-W estimator

Re: [R] Ridge Regression variable selection

2012-12-27 Thread Ben Bolker
Frank Harrell vanderbilt.edu> writes: > > Unlike L1 (lasso) regression or elastic net (mixture of L1 and L2), L2 norm > regression (ridge regression) does not select variables. Selection of > variables would not work properly, and it's unclear why you would want to > omit "apparently" weak vari

Re: [R] Ridge Regression variable selection

2012-12-27 Thread Frank Harrell
Unlike L1 (lasso) regression or elastic net (mixture of L1 and L2), L2 norm regression (ridge regression) does not select variables. Selection of variables would not work properly, and it's unclear why you would want to omit "apparently" weak variables anyway. Frank maths123 wrote > I have a .txt

Re: [R] ridge regression - covariance matrices of ridge

2011-08-07 Thread Ravi Varadhan
Hi Michael, The coefficients of ridge regression are given by: \beta^* = (X'X + k I)^{-1} X' y, (1) where k > 0 is the penalty parameter and I is the identity matrix. The ridge estimates are related to OLS estimates \beta as follows: \beta^* = Z \beta,

[R] ridge regression - covariance matrices of ridge coefficients

2011-08-06 Thread Michael Friendly
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 vecto

Re: [R] Ridge regression and mixed models

2010-10-04 Thread Dimitri Liakhovitski
Curious - what would be the purpose of this regression? On Mon, Oct 4, 2010 at 4:39 PM, harez...@post.harvard.edu wrote: > Dear R users, >  An equivalence between linear mixed model formulation and penalized > regression > models (including the ridge regression and penalized regression splines)

[R] Ridge regression and mixed models

2010-10-04 Thread harez...@post.harvard.edu
Dear R users, An equivalence between linear mixed model formulation and penalized regression models (including the ridge regression and penalized regression splines) has proven to be very useful in many aspects. Examples include the use of the lme() function in the library(nlme) to fit smooth

Re: [R] Ridge regression

2010-01-08 Thread Eleni Christodoulou
adhan.html > > > > > > > *From:* Eleni Christodoulou [mailto:elenic...@gmail.com] > *Sent:* Friday, January 08, 2010 11:18 AM > *To:* Ravi Varadhan > *Cc:* David Winsemius; r-help@r-project

Re: [R] Ridge regression

2010-01-08 Thread Ravi Varadhan
org Subject: Re: [R] Ridge regression I am sorry, I just pressed the "send" button by accident before completing my e-mail. The yest are the estimated values according to the ridge model. Is the way that I calculate them correct? Or should I cut the +coef(ridge.test)[1] term? Thanks a l

Re: [R] Ridge regression

2010-01-08 Thread Eleni Christodoulou
lth/People/Faculty_personal_pages/Varadhan.h%0Atml> >> >> >> >> >> >> >> >> >> -Original Message- >> From: r-help-boun...@r-project.org [mailto:r-h

Re: [R] Ridge regression

2010-01-08 Thread Eleni Christodoulou
han.h%0Atml> > > > > > > > > > -Original Message- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > On > Behalf Of Ravi Varadhan > Se

Re: [R] Ridge regression

2009-12-02 Thread Ravi Varadhan
2009 12:25 PM To: 'David Winsemius'; 'Eleni Christodoulou' Cc: r-help@r-project.org Subject: Re: [R] Ridge regression You are right that the ans$coef and coef(ans) are different in ridge regression, where `ans' is the object from lm.ridge. It is the coef(ans) that yields th

Re: [R] Ridge regression

2009-12-02 Thread Ravi Varadhan
mius Sent: Wednesday, December 02, 2009 11:04 AM To: Eleni Christodoulou Cc: r-help@r-project.org Subject: Re: [R] Ridge regression On Dec 2, 2009, at 10:42 AM, Eleni Christodoulou wrote: > Dear list, > > I have a couple of questions concerning ridge regression. I am using > the

Re: [R] Ridge regression

2009-12-02 Thread David Winsemius
On Dec 2, 2009, at 11:04 AM, David Winsemius wrote: On Dec 2, 2009, at 10:42 AM, Eleni Christodoulou wrote: Dear list, I have a couple of questions concerning ridge regression. I am using the lm.ridge(...) function in order to fit a model to my microarray data. Thus *model=lm.ridge(...)*

Re: [R] Ridge regression

2009-12-02 Thread David Winsemius
On Dec 2, 2009, at 10:42 AM, Eleni Christodoulou wrote: Dear list, I have a couple of questions concerning ridge regression. I am using the lm.ridge(...) function in order to fit a model to my microarray data. Thus *model=lm.ridge(...)* I retrieve some coefficients and some scales for each

[R] Ridge regression

2009-12-02 Thread Eleni Christodoulou
Dear list, I have a couple of questions concerning ridge regression. I am using the lm.ridge(...) function in order to fit a model to my microarray data. Thus *model=lm.ridge(...)* I retrieve some coefficients and some scales for each gene. First of all, I would like to ask: the real coefficients

Re: [R] Ridge regression [Repost]

2009-08-22 Thread Sabyasachi Patra
Thanks for the suggestion. But It will be more helpful if anybody comment on why I'm getting different outputs for three approaches. - Sabyasachi Patra PhD Scholar Indian institute of Technology Kanpur India. -- View this message in context: http://www.nabble.com/Ridge-regression--Repost--

Re: [R] Ridge regression [Repost]

2009-08-19 Thread Frank E Harrell Jr
Sabyasachi Patra wrote: Dear all, For an ordinary ridge regression problem, I followed three different approaches: 1. estimate beta without any standardization 2. estimate standardized beta (standardizing X and y) and then again convert back 3. estimate beta using lm.ridge() function X<-mat

[R] Ridge regression [Repost]

2009-08-19 Thread Sabyasachi Patra
Dear all, For an ordinary ridge regression problem, I followed three different approaches: 1. estimate beta without any standardization 2. estimate standardized beta (standardizing X and y) and then again convert back 3. estimate beta using lm.ridge() function X<-matrix(c(1,2,9,3,2,4,7,2,3,5,

Re: [R] ridge regression

2009-08-19 Thread Frank E Harrell Jr
If you didn't post anonymously I would have made a suggestion. Full names and affiliations should be given. Frank spime wrote: Dear all, I considered an ordinary ridge regression problem. I followed three different ways: 1. estimate beta without any standardization 2. estimate standardized

[R] ridge regression

2009-08-19 Thread spime
Dear all, I considered an ordinary ridge regression problem. I followed three different ways: 1. estimate beta without any standardization 2. estimate standardized beta (standardizing X and y) and then again convert back 3. estimate beta using lm.ridge() function X<-matrix(c(1,2,9,3,2,4,7,2,3

[R] ridge regression

2008-05-06 Thread Rodrigo Briceño
Thanks to all of you that helped me with the issues of bootstrapping and downloading packages to a local disk. As an starter I'm in the lower side of the learning curve, but this R software is awesome. What I like most is this kind of forums when people share their problems and we can find solution

[R] ridge regression

2008-05-06 Thread Rodrigo Briceño
Thanks to all of you that helped me with the issues of bootstrapping and downloading packages to a local disk. As an starter I'm in the lower side of the learning curve, but this R software is awesome. What I like most is this kind of forums when people share their problems and we can find solution