Displaying 20 results from an estimated 10000 matches similar to: "lars"
2010 Dec 06
2
How to get lasso fit coefficient(given penalty tuning parameter \lambda) using lars package
Hi, all,
I am using the lars package for lasso estimate. So I get a lasso
fit first:
lassofit = lars(x,y,type ="lasso",normalize=T, intercept=T)
Then I want to get coefficient with respect to a certain value of \lambda
(the tuning parameter), I know lars has three mode options c("step",
"fraction", "norm"), but can I use the \lambda value instead
2011 May 24
1
seeking help on using LARS package
Hi,
I am writing to seek some guidance regarding using Lasso regression with the
R package LARS. I have introductory statistics background but I am trying to
learn more. Right now I am trying to duplicate the results in a paper for
shRNA prediction "An accurate and interpretable model for siRNA efficacy
prediction, Jean-Philippe Vert et. al, Bioinformatics" for a Bioinformatics
project
2010 Dec 08
1
the output of function lars
Hi here is the code as example
lars is in package lars
> x<-matrix(rnorm(20*5,0,1),20,5)
> bs<-matrix(sample(seq(1:10),5),5,1)
> er<-rnorm(20,0,1)
> y<-x%*%bs+er
> lobj<-lars(x,y,type="lasso")
> names(lobj)
[1] "call" "type" "df" "lambda" "R2"
[6] "RSS"
2007 Aug 02
2
lasso/lars error
I'm having the exact problem outlined in a previous post from 2005 -
unfortunately the post was never answered:
http://tolstoy.newcastle.edu.au/R/help/05/10/15055.html
When running:
lm2=lars(x2,y,type="lasso",use.Gram=F)
I get an error:
Error in if (zmin < gamhat) { : missing value where TRUE/FALSE needed
...when running lasso via lars() on a 67x3795 set of predictors. I
2003 Jun 13
1
lars - lasso problem
hello
I tried to use lars() but neither with my own data nor with the sample data it
works. I get in both cases the following error prompt:
> data(diabetes)
> par(mfrow=c(2,2))
> attach(diabetes)
> x<-lars(x,y)
Error in one %*% x : requires numeric matrix/vector arguments
> x<-lars(x,y, type="lasso")
Error in one %*% x : requires numeric matrix/vector arguments
2009 Oct 27
1
lasso plot using LARS
When plotting a lars object, I cannot find a way to plot solid lines.
Even when the arguments breaks=F and lty="solid" are used, the vertical
lines at the break points do not plot but asterisks indicating the
breaks still plot as part of each path leaving solid lines broken up by
asterisks at the break points. I'm using the following code.
larsfit <-
2009 Jul 12
0
Plotting problem [lars()/elasticnet()]
Dear all,
I am using modified LARS algorithm (ref: The Adaptive Lasso and Its Oracle
Properties, Zou 2006) for adaptive lasso penalized linear regression.
1. w(j) <- |beta_ols(j)|^(-gamma) gamma>0 and j = 1,...,p
2. define x_new(j) <- x(j)*w(j)
3. apply LARS to solve modified lasso problem
out.adalasso <- lars(X_new,y,type="lasso") or enet(X_new,
2006 Sep 15
2
LARS for generalized linear models
Hi,
Is there an R implementation of least angle regression for binary response
modeling? I know that this question has been asked before, and I am also
aware of the "lasso2" package, but that only implements an L1 penalty, i.e.
the Lasso approach.
Madigan and Ridgeway in their discussion of Efron et al (2004) describe a
LARS-type algorithm for generalized linear models. Has
2012 Jul 12
1
lars package to do lasso
Dear all
I am using lars package to do lasso in R. I dont undesrtand what max.steps do?and how I can understand from the outputs to obtain the last steps in this packagethanks for your helpbest
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2005 May 31
3
lars / lasso with glm
We have been using Least Angle Regression (lars) to help identify
predictors in models where the outcome is continuous. To do so we have
been relying on the lars package. Theoretically, it should be possible
to use the lars procedure within a general linear model (glm) framework
- we are particular interested in a logistic regression model. Does
anyone have examples of using lars with logistic
2011 May 24
1
anyone using LARS package in R
Hi useR's,
Has anyone used the "Lars" package in R before? If so, is there any tutorial
(not manual) or worked out example online for this R package that one can go
through to figure out how one can use this package with lasso regression?
I appreciate any help I can get in this direction.
Sincerely,
Vishal
--
*Vishal Thapar, Ph.D.*
*Scientific informatics Analyst
Cold Spring
2012 Mar 21
1
glmnet() vs. lars()
dear all,
It appears that glmnet(), when "selecting" the covariates entering the
model, skips from K covariates, say, to K+2 or K+3. Thus 2 or 3
variables are "added" at the same time and it is not possible to obtain
a ranking of the covariates according to their importance in the model.
On the other hand lars() "adds" the covariates one at a time.
My question
2011 Jun 06
1
Lasso for k-subset regression
Dear R-users
I'm trying to use lasso in lars package for subset regression, I have a
large matrix of size 1000x100 and my aim is to select a subset k of the 100
variables.
Is there any way in lars to fix the number k (i.e. to select the best 10
variables)
library(lars)
aa=lars(X,Y,type="lasso",max.steps=200)
plot(aa,plottype="Cp")
aa$RSS
which.min(aa$RSS)
2008 Mar 13
0
lars with weights do not match with lm output
I got my posting bounced and sorry if I accidentally post twice.
I have been looking at 'lars' pkg and got puzzled by the behavior of
function 'lars'. I want to do weighted lasso regression and can't get a
match from lars output with lm output. Here is an example:
y = rnorm(10)
x = matrix(runif(50),nrow=10)
X = data.frame(y,x)
z = runif(10)
X = data.frame(y,x,z)
X$z = X$z /
2007 Jun 12
1
LASSO coefficients for a specific s
Hello,
I have a question about the lars package. I am using this package to get the coefficients at a specific LASSO parameter s.
data(diabetes)
attach(diabetes)
object <- lars(x,y,type="lasso")
cvres<-cv.lars(x,y,K=10,fraction = seq(from = 0, to = 1, length = 100))
fits <- predict.lars(object, type="coefficients", s=0.1, mode="fraction")
Can I assign
2007 Sep 19
1
Strange behaviour of lars method
Hi!
When I apply the lars (least-angle-regression) method to my data
(3655 features, only 355 data points, no I did not mistype), I
observe a strange behaviour:
1) The beta values tend to grow into real high values quite fast up
to a point where they overflow and get negative. The overflow is not
a problem, I don't need the last part of the analysis anyway, but why
do they just
2009 Jul 22
1
Question about the lars package
Hello,
I have a question about lars package, probably basic.
The returned values of lars function include R squares along the variable
selection path. However, such values are always slightly different from the
R squares returned by the regression function lm using the same models.
Anyone know the reasons?
Very important, and needs quick answers. Thanks a million!
--
View this message in
2013 May 04
2
Lasso Regression error
Hi all,
I have a data set containing variables LOSS, GDP, HPI and UE.
(I have attached it in case it is required).
Having renamed the variables as l,g,h and u, I wish to run a Lasso
Regression with l as the dependent variable and all the other 3 as the
independent variables.
data=read.table("data.txt", header=T)
l=data$LOSS
h=data$HPI
u=data$UE
g=data$GDP
matrix=data.frame(l,g,h,u)
2011 Jul 12
7
FW: lasso regression
Hi,
I am trying to do a lasso regression using the lars package with the following data (see attached):
FastestTime
WinPercentage
PlacePercentage
ShowPercentage
BreakAverage
FinishAverage
Time7Average
Time3Average
Finish
116.90
0.14
0.14
0.29
4.43
3.29
117.56
117.77
5.00
116.23
0.29
0.43
0.14
6.14
2.14
116.84
116.80
2.00
116.41
0.00
0.14
0.29
5.71
3.71
117.24
2007 May 17
0
New version 0.9-7 of lars package
I uploaded a new version of the lars package to CRAN,
which incorporates some nontrivial changes.
1) lars now has normalize and intercept options, both defaulted to TRUE,
which means the variables are scaled to have unit euclidean norm, and
an intercept is included in the model. Either or both can be set to FALSE.
2) lars has an additional type = "stepwise" option;
now the list is