Dear Rui, Kevin, Bryan and Nutter
Thank you so much for your very helpful hints!
Now I have extracted all the file names and managed to edit them using the
code (1)-(4) below and obtained the name format as I wanted
(1) files<-list.files(path = "myworking directory", pattern = NULL,
all.files = FALSE,
full.names = FALSE, recursive = FALSE,ignore.case = FALSE,
include.dirs = FALSE)
(2) filenames <- files[grep("[.]csv", files)]
[1] "512180_20120523150757.csv"
"513687_20120523181947.csv"
"513690_20120524112111.csv"
"521858_20120524091428.csv"
"523215_20120523123419.csv"
...(a few hundred more...)
(3) data_names <- gsub("[.]csv", "", filenames)
(4) NAME<- paste("Data",data_names, sep=".")
Up to here I got NAME containing all the names I'm going to use..
> NAME
[1] "Data.512180_20120523150757"
"Data.513687_20120523181947"
"Data.513690_20120524112111"
"Data.521858_20120524091428"
"Data.523215_20120523123419"
....
But I still haven't successfuly read the whole bunch of csv files into R
and name them as expected...e.g. I want to read "512180_20120523150757.csv"
into R and name it "Data.512180_20120523150757" and so on...
For a single file we can just write
Data.512180_20120523150757<-read.csv("512180_20120523150757.csv")
If any of the following commands (as you suggested) works, then my question
is sorted out. But I got error messages for every attempt...
(i)
> df.list <- lapply(seq_len(filenames), read.csv)
Error in seq_len(filenames) :
argument must be coercible to non-negative integer
In addition: Warning message:
In is.vector(X) : NAs introduced by coercion
> filenames
[1] "512180_20120523150757.csv" "513687_20120523181947.csv"
"513690_20120524112111.csv" "521858_20120524091428.csv"
[5] "523215_20120523123419.csv"...
(ii) None of the following code works...
myDir="myworking directory"
#for(i in 1:length(filenames)){assign(NAME[i], read.csv(file.path(myDir,
filenames[i])))}
#for(i in 1:5){assign(NAME[i], read.csv(file.path=myDir, filenames[i]))}
setwd("myworking directory")
#for(i in 1:5){assign(NAME[i], read.csv( filenames[i]))}
Warning messages:
1: In N[i] <- read.csv(filenames[i]) :
number of items to replace is not a multiple of replacement length
2: In N[i] <- read.csv(filenames[i]) :
number of items to replace is not a multiple of replacement length
3: In N[i] <- read.csv(filenames[i]) :
number of items to replace is not a multiple of replacement length
4: In N[i] <- read.csv(filenames[i]) :
number of items to replace is not a multiple of replacement length
5: In N[i] <- read.csv(filenames[i]) :
number of items to replace is not a multiple of replacement length
Seems I am getting there, but could you spot where my code went wrong
please??
Many thanks again!
HJ
On Fri, May 25, 2012 at 8:36 PM, Rui barradas <rui1...@sapo.pt> wrote:
> 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:
>
>> 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-boun...@r-project.org
>> [mailto:r-help-bounces@r-**project.org<r-help-boun...@r-project.org>]
>> On Behalf Of Kevin Wright
>> Sent: Friday, May 25, 2012 2:55 PM
>> To: HJ YAN
>> Cc: r-help@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<yhj...@googlemail.com> wrote:
>>
>>> Dear R users
>>>
>>>
>>> I am struggling from a data importing issue:
>>>
>>> I have some hundreds of csv files needed to be read into R for futher
>>> analysis. All those csv files are named in one of the three formats:
>>>
>>> (1) strings: e.g. London_Oxford street
>>> (2) Integer: e.g. 1234_5678
>>> (3) combined: e.g. London_1234
>>>
>>> I intend to use read.csv("xxxx_xxx.csv") but I only dealt with sigle
>>> documents before and if there are only no more than 20 files, I do not
>>> bother to search a more efficient way.
>>>
>>>
>>> Is there any claver way that I do not have to type in all these
>>> hundreds names by hand, maybe using a R package or write some code in
>>> some other languages if it is not too difficult to learn.
>>>
>>> Any thoughts/hints please??
>>>
>>> Many thanks in advance!
>>>
>>> HJ
>>>
>>> [[alternative HTML version deleted]]
>>>
>>> ______________________________**________________
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>>>
>>
>>
>> --
>> Kevin Wright
>>
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>>
>>
>> ==============================**=====
>>
>> Please consider the environment before printing this e-mail
>>
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>> and provide commented, minimal, self-contained, reproducible code.
>>
>
> ______________________________**________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/**listinfo/r-help<https://stat.ethz.ch/mailman/listinfo/r-help>
> PLEASE do read the posting guide http://www.R-project.org/**
> posting-guide.html <http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>
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