[R] Combining multiple datasets

[jim holtman]

Here is the way that I usually do it using lapply:

myData <- lapply(list.files(pattern=".RWL$"), function(.file)
read.rel(.file, header=TRUE))
# combine into a single dataframe
myDF <- do.call(rbind, myData)



On Thu, Aug 21, 2008 at 10:42 PM, Alison Macalady <ali at kmhome.org> wrote:
> Hi,
> I've tried to figure this out using Intro to R and help(), to no avail - I
> am new at this.
>
> I'm trying to write a script that will read multiple files from a directory
> and then merge them into a single new data frame.
> The original data are in a tree-ring specific format, and so I've first used
> a function (read.rwl) from the dplR package to read each file, translate
> each into a more intuitive time series format, and then put each new data
> frame into a single object, demo.Rwl:
>
>>demo.Rwl <- list.files(pattern=".RWL$"); for(i in demo.Rwl) { x <-
>> read.rwl(i, header=TRUE); assign(print(i, quote=FALSE), x)}
>
> This part seems to work.  Now, I want to be able to put all of the
> individual data frames contained in demo.Rwl into a single data frame,
> merging by rows (rows are calendar years in the time series). I think I know
> how to do this by typing each data set name into a merge:
>
>>merge(x,y..., by.x=0, all=TRUE )
>
> However, I'd like to be able to script something that will save me the time
> of typing in all of the individual data set names, as I will be repeating
> this operation many times with many different numbers of original input
> files. Is there a way to code a merge such that every individual data frame
> contained in demo.Rwl (a different number every time) gets combined into a
> single data set?
>
> Thanks for the help!
>
> Ali
>
> ______________________________________________
> 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.
>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?