[R] Import Multiple csv files and merge into one Master file

Joshua Wiley jwiley.psych at gmail.com
Fri Oct 8 05:28:22 CEST 2010


Hi Xing,

This depends somewhat on what you mean by "merge", and how many files
you are talking about.  Supposing you are dealing with few enough
files you can do it manually:

dat1 <- read.csv("yourfile1.csv")
dat2 <- read.csv("yourfile2.csv")
...
datn <- read.csv("yourfilen.csv")

If each file contains unique variables:

complete.dat <- cbind(dat1, dat2, ... , datn)

if each one is just a continuation rowise:

complete.dat <- rbind(dat1, dat2, ... , datn)

If they are all sort of related but in no consistent way, and do not need to be:

complete.dat <- list(dat1, dat2, ... , datn)

If you need some fancier merging than just columnwise or rowwise, look
at merge().  For documentation on these features see:

?data.frame # to find out more about data frames (which is what read.csv uses)
?list # for details about what a list is
?read.table
?read.csv # just a special wrapper for read.table
?cbind # for column binding
?rbind # for row binding
?merge # for more specialized merging
example(merge) # for examples using merge()

HTH,

Josh

On Thu, Oct 7, 2010 at 8:19 PM, XINLI LI <lihawaii at gmail.com> wrote:
> Dear R Group:
>
>    How to import multiple csv files and merge into one dataset.
>
> Thanks and Regards,
>
>   Xing
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
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>



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



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