Thanks a million for all help provided!! I can do what I intend to using the "for loop". However, I'm still eager to try the list.files approach. Here is the error message that I got using Ivan's code:
> list_of_dataset <- do.call(read.table, file_names) Error in do.call(read.table, file_names) : second argument must be a list Please advise. Ray On Sun, Jan 27, 2013 at 10:57 PM, Ivan Calandra < ivan.calan...@u-bourgogne.fr> wrote: > Hi Ray! > > I'm insisting with list.files...! > > What about like this (untested)? > file_names <- list.files(path="C:/.../data", pattern=".dat$", > full.names=TRUE) > list_of_dataset <- do.call(read.table, file_names) > > Let me know if this helps! > Ivan > > -- > Ivan CALANDRA > Université de Bourgogne > UMR CNRS/uB 6282 Biogéosciences > 6 Boulevard Gabriel > 21000 Dijon, FRANCE+33(0)3.80.39.63.06ivan.calan...@u-bourgogne.fr > http://biogeosciences.u-bourgogne.fr/calandra > > Le 26/01/13 10:03, Ray Cheung a écrit : > > Thanks for your commands, Ivan and Michael! However, I am still not > producing the right codes. Would you please help me on this? I've written > the following codes. Please comment. Thank you very much. > > Task: Reading data1.dat to data1000.dat (with missing files) into R. > Missing files can be omitted in the list. > > ###FUNCTION TO READ FILES > little_helpful <- function(n) { > file_name <- paste0("C:/.../data", n, ".dat") > read.table(file_name) > } > > ###RETURN AN OBJECT WHICH CHECKS FOR THE EXISTENCE OF FILES > check <- function(n) { > a <- ifelse(file.exists(paste0("C:/.../data", n, ".dat")), 1, 0) > a > } > ###Combining the functions > IMPORT <- function(n) { > L <- check(1:n) > for (i in 1:n) { > if (L[i] == 1) > list_of_datasets <- lapply(i, little_helpful) else list_of_datasets > <- 0 > } > list_of_datasets > } > > Thanks for all comments. > > Best Regards, > Ray > > On Fri, Jan 25, 2013 at 5:48 PM, Ivan Calandra < > ivan.calan...@u-bourgogne.fr> wrote: > >> Hi, >> >> Not sure this is what you need, but what about list.files()? >> It can get you all the files from a given folder, and you could then work >> this list with regular expressions for example. >> >> HTH, >> Ivan >> >> -- >> Ivan CALANDRA >> Université de Bourgogne >> UMR CNRS/uB 6282 Biogéosciences >> 6 Boulevard Gabriel >> 21000 Dijon, FRANCE >> +33(0)3.80.39.63.06 >> ivan.calan...@u-bourgogne.fr >> http://biogeosciences.u-bourgogne.fr/calandra >> >> Le 25/01/13 10:00, R. Michael Weylandt a écrit : >> >>> On Fri, Jan 25, 2013 at 6:11 AM, Ray Cheung <ray1...@gmail.com> wrote: >>> >>>> Dear Michael, >>>> >>>> Thanks for your codes. However, lapply does not work in my case since >>>> I've >>>> some files missing in the data (say, the file data101.dat). Do you have >>>> any >>>> suggestions on this?? Thank you very much. >>>> >>>> You could simply add a test using file.exists() but I'm not sure what >>> you want to do with the M matrix then -- omit the slice (so the others >>> are all shifted down one) or fill it entirely with NA's. >>> >>> Michael >>> >>> ______________________________________________ >>> R-help@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. >>> >>> >> ______________________________________________ >> R-help@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. >> > > [[alternative HTML version deleted]]
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