How to intantiate a list of data.frames?

Hi Josh,

Sorry, your examples have equal number of rows in both df and df2.
In my situation they haven't.
Strangely, your solution have worked only when I am copy post the code into
the command line.
If I use the code inside of a function I get an error at:
return(ds)
ERROR: arguments imply differing number of rows

Thanks,
Rui

Date: Sat, 21 May 2011 11:46:05 -0700
Subject: Re: [R] How to intantiate a list of data.frames?
From: jwiley.psych at gmail.com
To: ruimaximo at hotmail.com
CC: r-help at r-project.org

Hi Rui,

Here is one option:

ds <- vector("list", 6)
for(i in 1:6) ds[[i]] <- list(df = mtcars[, c(i, i + 2)], df2 =
mtcars[, c(i, i + 2)] + 10)

another could be:

altds <- lapply(1:6, function(x) {
list(df = mtcars[, c(x, x + 2)], df2 = mtcars[, c(x, x + 2)] + 10)
})

all.equal(ds, altds)

For some documentation, see

?vector
?lapply

Cheers,

Josh

On Sat, May 21, 2011 at 10:47 AM, Rui Maximo <ruimaximo at hotmail.com>
wrote:

Hello,

?I am newbie to R and I want to do this:

for(i in 1:6)
{
? ? ? ?ds[i] <- list(df=data.frame(oilDF[,1],oilDF[,i+2]),
df2=data.frame(oilDF2[,1],oilDF2[,i+2]))
}

#oilDF and oilDF2 are 2 data frames with several columns. They have
different number of rows

#I want to have for example ds[1]$df, ds[1]$df2 with the respective
data.frames.
#How can I instantiate a list of data.frames pairs with different number
of rows?

Thank you,
Rui

? ? ? ?[[alternative HTML version deleted]]

--
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/