[R] densities from a list with data.frames
cskiadas at gmail.com
Fri Apr 11 14:09:24 CEST 2008
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.
Department of Mathematics and Computer Science
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
>>> 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.
>> lapply(l, function(x) density(x[,1]))
>> Mathematical Sciences Unit
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