[R] Importing multiple text files with lapply.

jim holtman jholtman at gmail.com
Tue Jan 18 01:44:03 CET 2011


It sounds like you want to use 'readLines' and not 'read.table'

> x <- readLines(textConnection("January 11, 2009
+ January 11, 2009
+ October 19, 2008
+ October 13, 2008
+ August 16, 2008
+ June 19, 2008
+ April 19, 2008
+ April 16, 2008
+ February 9, 2008
+ September 2, 2007"))
> closeAllConnections()
> x
 [1] "January 11, 2009"  "January 11, 2009"  "October 19, 2008"
"October 13, 2008"  "August 16, 2008"
 [6] "June 19, 2008"     "April 19, 2008"    "April 16, 2008"
"February 9, 2008"  "September 2, 2007"
>

What exactly are you going to do with the data after you read it in?

On Mon, Jan 17, 2011 at 6:22 PM, Simon Kiss <simonjkiss at yahoo.ca> wrote:
> Dear jim,
> Yes, it's true, the data are separated onto new lines as follows:
> January 11, 2009
> January 11, 2009
> October 19, 2008
> October 13, 2008
> August 16, 2008
> June 19, 2008
> April 19, 2008
> April 16, 2008
> February 9, 2008
> September 2, 2007
>
> I tried your attempt and it didn't work either; it returned the error message:
> Error in FUN(X[[1L]], ...) :
>  'file' must be a character string or connection
>
> On 2011-01-17, at 2:02 PM, jim holtman wrote:
>
>> try:
>>
>> mylist <- lapply(a, read.table, header = TRUE, sep = '\n')
>>
>> also is the separator really '\n' meaning a new-line?  What exactly
>> does the data look like?
>>
>> On Mon, Jan 17, 2011 at 11:47 AM, Simon Kiss <simonjkiss at yahoo.ca> wrote:
>>> Hello,
>>> I'm trying to read in 50 text filess with dates as content to create a list of tables.
>>>
>>> a is the list of filenames that need to be read in.
>>>
>>> The following command returns the following error
>>> mylist<-lapply(a, read.table(header=TRUE, sep="\n"))
>>>
>>> Error in read.table(header = TRUE, sep = "\n") :
>>>  element 1 is empty;
>>>   the part of the args list of 'is.character' being evaluated was:
>>>   (file)
>>>
>>> Does anyone have any suggestions?
>>> Yours, Simon Kiss
>>> *********************************
>>> Simon J. Kiss, PhD
>>> Assistant Professor, Wilfrid Laurier University
>>> 73 George Street
>>> Brantford, Ontario, Canada
>>> N3T 2C9
>>> Cell: +1 519 761 7606
>>>
>>> ______________________________________________
>>> R-help at 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.
>>>
>>
>>
>>
>> --
>> Jim Holtman
>> Data Munger Guru
>>
>> What is the problem that you are trying to solve?
>
> *********************************
> Simon J. Kiss, PhD
> Assistant Professor, Wilfrid Laurier University
> 73 George Street
> Brantford, Ontario, Canada
> N3T 2C9
> Cell: +1 519 761 7606
>
>
>
>
>
>
>
>
>
>
>



-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?



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