R help - Dec 2012 - how to get a value from a list (using paste function)?

Dear my R friends,

I want to get a number from a list using paste function.
In my example,
lambda.rule <- "lambda.1se"
cvtest is a list (result from cv.glmnet)
and
cvtest$lambda.1se
[1] 1.308973

I want to call the value using paste function.
I used get function but there was an error.
test <-  get(paste("cvtest$",lambda.rule, sep=""))
Error in get(paste("cvtest$", lambda.rule, sep = "")) :
  object 'cvtest$lambda.1se' not found

Do you guys know how to solve this issue?

Thank you so much in advance and merry Christmas!

Soyeon

HI,

It guess ?get() does not work with $ elements.
x1 <- list(a=c(1,2), b = c(2,4), c=c(4,5,6))
#this works
?get(paste("x","1",sep=""))["a"]
#$a
#[1] 1 2
#or
?get(paste("x","1",sep=""))[[2]]
#[1] 2 4
A.K.






----- Original Message -----
From: Soyeon Kim <yunni0731 at gmail.com>
To: r-help <r-help at r-project.org>
Cc: 
Sent: Tuesday, December 18, 2012 12:34 PM
Subject: [R] how to get a value from a list (using paste function)?

Dear my R friends,

I want to get a number from a list using paste function.
In my example,
lambda.rule <- "lambda.1se"
cvtest is a list (result from cv.glmnet)
and
cvtest$lambda.1se
[1] 1.308973

I want to call the value using paste function.
I used get function but there was an error.
test <-? get(paste("cvtest$",lambda.rule, sep=""))
Error in get(paste("cvtest$", lambda.rule, sep = "")) :
? object 'cvtest$lambda.1se' not found

Do you guys know how to solve this issue?

Thank you so much in advance and merry Christmas!

Soyeon

______________________________________________
R-help at r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Soyeon-

A possible solution:

get(lambda.rule,envir=list2env(cvtest))


On Tue, Dec 18, 2012 at 12:34 PM, Soyeon Kim <yunni0731@gmail.com> wrote:
> Dear my R friends,
>
> I want to get a number from a list using paste function.
> In my example,
> lambda.rule <- "lambda.1se"
> cvtest is a list (result from cv.glmnet)
> and
> cvtest$lambda.1se
> [1] 1.308973
>
> I want to call the value using paste function.
> I used get function but there was an error.
> test <-  get(paste("cvtest$",lambda.rule, sep=""))
> Error in get(paste("cvtest$", lambda.rule, sep = "")) :
>   object 'cvtest$lambda.1se' not found
>
> Do you guys know how to solve this issue?
>
> Thank you so much in advance and merry Christmas!
>
> Soyeon
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>
>
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