On 5/21/20 9:24 AM, YANJUN CHEN via R-help wrote:
Dear R community,
I am new to R—did some online tutorials and exercises in R playground. I was
wondering if I could seek guidance on the following matter.
I have a set of 403 .csv files. Each.csv file contains the same layouts and
distinguished by subject ID and date in the file name. The dataset looks like
this:
Sub1-20170305.csv
Sub2-20180214.csv
…
Sub403-20191109.csv
Something along the lines of:
?regex ; ?sub
?read.table
?data.frame
?do.call
?rbind
myfiles <- lapply( list.files(your_path) , # each file name will be
passed to anonymous function
function(nm) data.frame( subID = sub("-.+",
"", nm), # remove chars after "-"
date=sub("^.+-(.{8})[.]csv", "\\1", nm), #extract date as capture class
#assuming all files have
same number of columns with no headers
read.table(
paste0(your_path, nm) )
big_file <- do.call(rbind, myfiles)
I will use rbind function to combine 403 csv files in a single file (myFile). I
will create two new variables (use mutate function) in myFile (subject ID and
date). Is there a way to subtract subject ID (shown as “Sub1, 2,,,403”) and
date from the name of the csv file and then place them in “subject ID” and
“date” in myFile?
Any info on the issue itself or where to look for will be appreciated.
If you search StackOverflow or Rseek with topic terms " stacking
multiple data files" you should find many worked examples.
Thanks,
CJ
[[alternative HTML version deleted]]
You should now read the Posting Guide which will explain why you should
NOT post in HTML.
Best;
David.
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
