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Reading a bunch of csv files into R

10 messages · Kevin Wright, Bryan Hanson, Nutter, Benjamin +3 more

Original
Kevin Wright
# 
See ?dir

Assign the value to a vector and loop over the elements of the vector.

Kevin
On Fri, May 25, 2012 at 12:16 PM, HJ YAN <yhj204 at googlemail.com> wrote:

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Bryan Hanson
    

    

      
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HJ, try something like this:

   files <- list.files(pattern = "\\.(csv|CSV)$")

    for (i in 1:length(files)) {
            temp <- read.csv(files[i], header = FALSE)
 ... do whatever you want with the contents of temp...
    }

Bryan
***********
Bryan Hanson
Professor of Chemistry & Biochemistry
DePauw University

        
On May 25, 2012, at 1:16 PM, HJ YAN wrote:

        

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Nutter, Benjamin
    

    

      
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For example:

myDir <- "some file path" 
filenames <- list.files(myDir)
filenames <- filenames[grep("[.]csv", filenames)]

data_names <- gsub("[.]csv", "", filenames)

for(i in 1:length(filenames)) assign(data_names[i], read.csv(file.path(myDir, filenames[i])))

?

 Benjamin Nutter |??Biostatistician   ? |??Quantitative Health Sciences
? Cleveland Clinic?   | ?9500 Euclid Ave.? | ?Cleveland, OH 44195? |?(216) 445-1365


-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Kevin Wright
Sent: Friday, May 25, 2012 2:55 PM
To: HJ YAN
Cc: r-help at r-project.org
Subject: Re: [R] Reading a bunch of csv files into R

See ?dir

Assign the value to a vector and loop over the elements of the vector.

Kevin

        
On Fri, May 25, 2012 at 12:16 PM, HJ YAN <yhj204 at googlemail.com> wrote:

            

      
      
      
    

        

      
      
    

        
--
Kevin Wright

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      Rui Barradas
    

    

      
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Hello,

Or maybe put the data frames in a list

df.list <- lapply(seq_len(filenames), read.csv, ...) # '...other...' are 
options you might want to pass, (like headers=TRUE)
names(df.list) <- data_names

Now access the data frames by number in the list or by name in data_names.

Hope this helps,

Rui Barradas
Em 25-05-2012 20:08, Nutter, Benjamin escreveu:

            

      
      
      
    

        

      
      
    

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Rich Shepard
    

    

      
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On Fri, 25 May 2012, HJ YAN wrote:

        

            

      
      
      
    

        
I'd put the list of commands in a shell script; e.g.,

# import_files.R
read_csv("file1.csv", header = T, sep = ',')
read_csv("file2.csv", header = T, sep = ',')

etc.

   Then, within a R session, run

source("/full/path/to/import_files.R")

or, on the command line,

R CMD BATCH /full/path/name/to/import_files.R

   You'll still need to list all the files individually unless you use a
loop. I've not tried that so someone more experienced will advise you on
that.

Rich

  
  


  


      

    

    
2 days later