Displaying 9 results from an estimated 9 matches for "l1ce".
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2005 Feb 11
1
Help concerning Lasso::l1ce
Hi,
First, when I try the example Prostate with bound 0.44
(as in the manual), I got a different result:
> l1c.P <- l1ce(lpsa ~ ., Prostate, bound=0.44)
> l1c.P
....
Coefficients:
(Intercept) lcavol lweight age
lbph svi
1.0435803 0.4740831 0.1953156 0.0000000
0.0000000 0.3758199
lcp gleason pgg45
0.0000000 0.0000000 0.0000000
The relative L1 boun...
2007 Aug 28
1
The l1ce function in lasso2: The bound and absolute.t parameters.
Dear all,
I am quite puzzled about the bound and absolute.t arguments to the l1ce function in the lasso2 package. (The l1ce function estimates the regression parameter b in a regression model y=Xb+e subject to the constraint that |b|<t for some value t).
The doc says:
bound numeric, either a single number or a vector: the constraint(s) that is/are put onto the L1 norm of t...
2003 Dec 08
1
trouble with predict.l1ce
Dear R-help,
I am having trouble with the predict function in lasso2. For example:
> data(Iowa)
> l1c.I <- l1ce(Yield ~ ., Iowa, bound = 10, absolute.t=TRUE)
> predict (l1c.I) # this works is fine
> predict (l1c.I,Iowa)
Error in eval(exper,envir, enclos) : couldn't find function "Yield"
And I have similar trouble whenever I use the newdata argument in
prediction.
thanks in...
2012 Mar 27
2
lasso constraint
...straint 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"] <- Prostate[, "lpsa"]
l1ce(lpsa ~ . , pros, bound = 0.44)
I can't figure out what dose 0.44 come from. On the paper it said it was
from generalized cross-validation and it is the optimal choice.
paper name: Regression Shrinkage and Selection via the Lasso
author: Robert Tibshirani
--
View this message in cont...
2003 Dec 04
2
predict.gl1ce question
Hi,
I'm using gl1ce with family=binomial like so:
>yy
succ fail
[1,] 76 23
[2,] 32 67
[3,] 56 43
...
[24,] 81 18
>xx
c1219 c643
X1 0.04545455 0.64274145
X2 0.17723669 0.90392792
...
X24 0.80629054 0.12239320
>test.gl1ce <- gl1ce(yy ~ xx, family = binomi...
2007 Nov 09
1
help with lasso2 package
....1861905 -2.891821
4 1.938780097 0.7469251 1.2537781 -1.212992
5 -0.332370358 1.1943637 0.7114278 -1.830441
modF<-formula(F ~ V1 + V2 + V3) #no error message
#general least squares model works fine
glm.F <- glm(modF, data = F2, family = gaussian)
#But there are unresolved errors with gl1ce
gl1F<-gl1ce(modF, data=F2, family=gaussian)
Error in family(family) : link "family" not available for
gaussian family; available links
are 'inverse', 'log', 'identity'
> gl1F<-gl1ce(modF, data=F2, family=gaussian(link="identity"))...
2007 Jul 25
1
question on using "gl1ce" from "lasso2" package
Hi,
I tried several settings by using the "family=gaussian"
in "gl1ce", but none of them works.
For the case "glm" can work.
Here is the error message I got:
> glm(Petal.Width~Sepal.Length+Sepal.Width+Petal.Length
,data=iris,family=gaussian())
> gl1ce(Petal.Width~Sepal.Length+Sepal.Width+Petal.Length
,data=iris,family=gaussian())
Error in eval(e...
2007 Apr 12
1
Question on ridge regression with R
Hi,
I am working on a project about hospital efficiency. Due to the high
multicolinearlity of the data, I want to fit the model using ridge
regression. However, I believe that the data from large hospital(indicated
by the number of patients they treat a year) is more accurate than from
small hosptials, and I want to put more weight on them. How do I do this
with lm.ridge?
I know I just need
2007 Oct 02
0
Variable selection in R
...ulation ranges I
suspect could show different behaviours in the form of statistically
different means as per ANOVA analysis. Coming back to my original variable
selection need, here's what I did.
First : regular lm
Second : step
Third : all-subsets (regsubsets, package leaps)
Fourth : lasso (l1ce, package lasso2)
Fifth : (I meant to use the lars package, but it does not allow for
formulas; I know I could cast my dataset as matrices, but I didn't find an
easy way of doing this and I figured I had enough options already)
I'm trying to make sense of the information that is sent back...