[R] readPDF() -- unsure how to install xpdf to make this work?

[Uwe Ligges]

clair.crossupton at googlemail.com wrote:
> Hello, I was just wondering if you had found a solution? I am having
> the same difficulty of converting pdf's into plain text documents in
> R. I originally thought I could use the readLines() function, but as
> you can see below that did not work.

Why the hell should it? It is designed to read *text* files. And what 
you get below is exactly how your PDF file looks like if you read it as 
text which it is NOT. Why do you not also go the readPDF() way (and yes, 
it is not always possible nor reliable to go that way).

Uwe Ligges



> 
> R> my.destfile <- "C:\\Documents and Settings\\clair\\Desktop\\test\\r-
> intro.pdf"
> R> my.url <- "http://cran.r-project.org/doc/manuals/R-intro.pdf"
> R> download.file(url = my.url, destfile=my.destfile, mode='wb')
> R> txt <- readLines(my.destfile)
> R> txt
> [1]
> "%PDF-1.4"
> [2]
> "%ÐÔÅØ"
> [3] "1 0 obj
> <<"
> [4] "/Length 587
> "
> [5] "/Filter /
> FlateDecode"
> [6]
> ">>"
> [7]
> "stream"
> [8] "xÚmTM¢@\020½ó+z\017&ÎÁ±?\024tBL\020$ñ°ãd4›½*´.‰\002\001<øï·_•èÌf
> \017’W¯_wÕ«îrðãc;Šòê`GæUŠOÛV×&³£øç¾ö\006ƒ¤Ê®\027[vïÖæ6ïWÛ7ñÑTÙÖvb
> \030¯“uYt/N¼.³ó5·½êÿ¢¥=\025åS‚<b¸³¿G›"
> 
> 
> Warm Regards,
> Clair
> 
> On 13 Nov, 15:10, Tony Breyal <tony.bre... at googlemail.com> wrote:
>> Dear R-Help,
>>
>> I need to convert a set of '.pdf' files into an equivalent set of
>> '.txt' files. This is so that i can do some text mining on the
>> content.
>>
>> In the latest R-News letter (http://cran.r-project.org/doc/Rnews/
>> Rnews_2008-2.pdf), the package 'tm' for text mining is mentioned. In
>> that lovely package, there is a function called 'readPDF()'. In order
>> to use this, ?readPDF says
>>
>>     "Note that this PDF reader needs both the tools pdftotext and
>> pdfinfo installed and accessable on your system."
>>
>> These tools are available fromhttp://www.foolabs.com/xpdf/download.html
>>
>> I am able to download this and use it easily from a dos window to
>> convert a pdf file into a txt file.
>>
>> Question: how do i make these tools available to R, so that i can use
>> the readPDF() function?
>>
>> Thank you in advance for any help, and I hope the above made sense.
>> Tony Breyal
>>
>> ###OS = Windows Vista Ultimate>> sessionInfo()
>>
>> R version 2.8.0 (2008-10-20)
>> i386-pc-mingw32
>>
>> locale:
>> LC_COLLATE=English_United Kingdom.1252;LC_CTYPE=English_United Kingdom.
>> 1252;LC_MONETARY=English_United Kingdom.
>> 1252;LC_NUMERIC=C;LC_TIME=English_United Kingdom.1252
>>
>> attached base packages:
>> [1] grid      stats     graphics  grDevices utils     datasets
>> methods   base
>>
>> other attached packages:
>> [1] tm_0.3-1           XML_1.98-1         Snowball_0.0-3
>> RWeka_0.3-14       rJava_0.6-0        Matrix_0.999375-16
>> lattice_0.17-15    filehash_2.0
>>
>> loaded via a namespace (and not attached):
>> [1] proxy_0.4-1
>>
>> ______________________________________________
>> R-h... at r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> 
> 
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