[R] how to read a file containing a series filename

jim holtman jholtman at gmail.com
Wed Mar 7 15:48:39 CET 2012


you have to tell 'scan' to read characters with

what = ''



On Wed, Mar 7, 2012 at 9:44 AM, Jie Tang <totangjie at gmail.com> wrote:
> there is something wrong :
>
> scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings,  :
>   scan() needs 'a real', but not 'H20100903.TXT'
>
> 2012/3/7 jim holtman <jholtman at gmail.com>
>>
>> This works fine for me; look at your options on 'scan':
>>
>>
>> > x <- scan(text = "H20100902.TXT
>> + H20100903.TXT
>> + H20100904.TXT
>> + H20100905.TXT
>> + H20100906.TXT
>> + H20100907.TXT
>> + H20100908.TXT", what = '')
>> Read 7 items
>> > cat(x, file = 'file.txt', sep = '\n')  # create the 'file.txt'
>> >
>> > files <- scan('file.txt', what = '')  # read names from the file
>> Read 7 items
>> > files  # display the names
>> [1] "H20100902.TXT" "H20100903.TXT" "H20100904.TXT" "H20100905.TXT"
>> "H20100906.TXT"
>> [6] "H20100907.TXT" "H20100908.TXT"
>> >
>>
>>
>> On Wed, Mar 7, 2012 at 8:49 AM, Jie Tang <totangjie at gmail.com> wrote:
>> > hi everyone .
>> > I have a group of files that needs to be read in .
>> > And I put their filename into one file with the name "file.txt"
>> >
>> > And in the file.txt,the filename are shown as below :
>> > H20100902.TXT
>> > H20100903.TXT
>> > H20100904.TXT
>> > H20100905.TXT
>> > H20100906.TXT
>> > H20100907.TXT
>> > H20100908.TXT
>> >
>> > Now I want to read these file from the file.txt by such  codes:
>> >
>> >
>> > filename <-("file.txt")
>> >
>> > pp <- scan(filename,what=list(""),sep=" ")
>> >
>> > but R shows  that :
>> >> pp
>> > [[1]]
>> >
>> > that is pp is just one dimension data?
>> >
>> > but when I type
>> >>pp[1]
>> > the filenames are shown.
>> >
>> > How could I read these filenames into one array
>> > and so that .I can read the data by such a command ?
>> >
>> > ddata<-scan(pp[2],what=datalist,na.strings = 999)
>> >
>> > thank you .
>> > --
>> > TANG Jie
>> > Email: totangjie at gmail.com
>> > Tel: 0086-2154896104
>> > Shanghai Typhoon Institute,China
>> >
>> >        [[alternative HTML version deleted]]
>> >
>> > ______________________________________________
>> > 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?
>> Tell me what you want to do, not how you want to do it.
>
>
>
>
> --
> TANG Jie
> Email: totangjie at gmail.com
> Tel: 0086-2154896104
> Shanghai Typhoon Institute,China



-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.



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