[R] densities from a list with data.frames

[Antje]

Probably, I should read emails more carefully... sorry!!!
Of course, this solves my problem.

Thank you very much!


Charilaos Skiadas schrieb:
> Did you try Richie's suggestion? The x[,1] part will pick out the first 
> column of the data frame. Seems to do exactly what you asked for.
> 
> Haris Skiadas
> Department of Mathematics and Computer Science
> Hanover College
> 
> On Apr 11, 2008, at 7:57 AM, Antje wrote:
> 
>> Of course, I know, but I cannot apply the function "density" to a data 
>> frame
>> (which is the element of the list) but to a vector coming from a data 
>> frame.
>> That's my problem I'd like to solve...
>>
>>
>>
>> Richard.Cotton at hsl.gov.uk schrieb:
>>>> I have a list which consists of data frames (all data frames have the
>>> same
>>>> amount and type of columns but different length).
>>>> Now, I'd like to calculate for each data frame in the list the
>>>> density function
>>>> of the values of the fist column ($V1).
>>>>
>>>> This list could be an example:
>>>>
>>>> l <- list( data.frame(rnorm(100)), data.frame(rnorm(20)), data.
>>>> frame(rnorm(200)) )
>>>
>>> If you want to do the same thing to every element of a list, lapply (or
>>> sapply) is your friend.
>>> Try:
>>>
>>> lapply(l, function(x) density(x[,1]))
>>>
>>> Regards,
>>> Richie.
>>>
>>> Mathematical Sciences Unit
>>> HSL
>>>
> 
> 
> 
>