[R] how to get a value from a list (using paste function)?

[Uwe Ligges]

On 27.12.2012 08:09, Heramb Gadgil wrote:
> eval(parse(text=paste0("cvtest$",lambda.rule)))

No, never ever!

There is an R idiom made for it:

cvtest[[lambda.rule]]

Uwe Ligges






> I hope this works.
>
> On Wed, Dec 19, 2012 at 12:57 AM, Thomas Stewart
> <tgs.public.mail at gmail.com>wrote:
>
>> Soyeon-
>>
>> A possible solution:
>>
>> get(lambda.rule,envir=list2env(cvtest))
>>
>>
>> On Tue, Dec 18, 2012 at 12:34 PM, Soyeon Kim <yunni0731 at 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 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.
>>>
>>>
>>>
>>
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>>
>> ______________________________________________
>> 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.
>>
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> 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.
>