Displaying 20 results from an estimated 1000 matches similar to: "lasso based selection for mixed model"
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)
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
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 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 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
2011 May 02
2
Lasso with Categorical Variables
Hi! This is my first time posting. I've read the general rules and
guidelines, but please bear with me if I make some fatal error in
posting. Anyway, I have a continuous response and 29 predictors made
up of continuous variables and nominal and ordinal categorical
variables. I'd like to do lasso on these, but I get an error. The way
I am using "lars" doesn't allow for the
2009 Aug 21
1
LASSO: glmpath and cv.glmpath
Hi,
perhaps you can help me to find out, how to find the best Lambda in a
LASSO-model.
I have a feature selection problem with 150 proteins potentially
predicting Cancer or Noncancer. With a lasso model
fit.glm <- glmpath(x=as.matrix(X), y=target, family="binomial")
(target is 0, 1 <- Cancer non cancer, X the proteins, numerical in
expression), I get following path (PICTURE
2012 Mar 27
2
lasso constraint
In the package lasso2, there is a Prostate Data. To find coefficients in the
prostate cancer example we could impose L1 constraint on the parameters.
code is:
data(Prostate)
p.mean <- apply(Prostate, 5,mean)
pros <- sweep(Prostate, 5, p.mean, "-")
p.std <- apply(pros, 5, var)
pros <- sweep(pros, 5, sqrt(p.std),"/")
pros[, "lpsa"] <-
2012 Jun 05
1
Piecewise Lasso Regression
Hi All,
I am trying to fit a piecewise lasso regression, but package Segmented does not work with Lars objects.
Does any know of any package or implementation of piecewise lasso regression?
Thanks,
Lucas
2010 Jul 31
1
Feature selection via glmnet package (LASSO)
Hello,
I'm trying to select features of cetain numbers(like 100 out of 1000) via
LASSO, based on multinomial model, however, it seems the glmnet package
provides a very sparse estimation of coefficients(most of coefficients are
0), which selects very few number of variables, like only 10, based on my
easy dataset.
I try to connect the choice of lambda to the selecting
2010 Dec 22
1
code of applying lasso method in cox model
I also hope to get the code of using lasso method in the cox model.Could you please send me one?
Thank you so much!!!
2009 Mar 17
1
Double Cross validation for LASSO
Dear R user,
I am looking for a code on double cross validation in
LASSO , one for optimizing the parameter and other one is for MSEP. If any
one have it, please foroward to me. I am using different package like LARS,
chemometric etc.
Thanks in advance
Alex
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2001 May 23
2
help: exponential fit?
Hi there,
I'm quite new to R (and statistics),
and I like it (both)!
But I'm a bit lost in all these packages,
so could someone please give me a hint
whether there exists a package for fitting
exponential curves (of the type
t --> \sum_i a_i \exp( - b_i t))
on a noisy signal?
In fact monoexponential decay + polynomial growth
is what I'd like to try.
Thanks in advance,
2002 Mar 01
2
step, leaps, lasso, LSE or what?
Hi,
I am trying to understand the alternative methods that are available for
selecting
variables in a regression without simply imposing my own bias (having "good
judgement"). The methods implimented in leaps and step and stepAIC seem to
fall into the general class of stepwise procedures. But these are commonly
condemmed for inducing overfitting.
In Hastie, Tibshirani and Friedman
2013 Jul 06
1
problem with BootCV for coxph in pec after feature selection with glmnet (lasso)
Hi,
I am attempting to evaluate the prediction error of a coxph model that was
built after feature selection with glmnet.
In the preprocessing stage I used na.omit (dataset) to remove NAs.
I reconstructed all my factor variables into binary variables with dummies
(using model.matrix)
I then used glmnet lasso to fit a cox model and select the best performing
features.
Then I fit a coxph model
2010 Apr 06
1
Caret package and lasso
Dear all,
I have used following code but everytime I encounter a problem of not having
coefficients for all the variables in the predictor set.
# code
rm(list=ls())
library(caret)
# generating response and design matrix
X<-matrix(rnorm(50*100),nrow=50)
y<-rnorm(50*1)
# Applying caret package
con<-trainControl(method="cv",number=10)
data<-NULL
data<- train(X,y,
2013 Nov 29
1
Lasso function that can handle NA values
Hi everyone,
I have a large dataset with missing values. I tried using glmnet, but it seems that it cannot handle NA values in the design matrix. I also tried lars, but I get an error too. Does anyone know of any package for computing the lasso solution which handles NA values?
2007 Mar 15
1
Model selection in LASSO (cross-validation)
Hi, I know how to use LASSO for model selection based on the Cp criterion.
I heard that we can also use cross validation as a criterion too. I used
cv.lars to give me the lowest predicted error & fraction. But I'm short of
a step to arrive at the number of variables to be included in the final
model. How do we do that? Is it the predict.lars function? i tried >
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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