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string functions

6 messages · zubin, jim holtman, Gabor Grothendieck +1 more

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Hello, trying to locate all the string commands in the base version of 
R, can't seem to find an area that describes them. I am in need to do 
some serious parsing of text data to create my dataset.  Is there a 
summary link to all the character operators?  string manipulations that 
would help in parsing text.
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On Sep 14, 2008, at 1:53 PM, zubin wrote:

            
A bit of use of the ? operator on paste and strsplt produces (among  
other things:

See Also
String manipulation with as.character, substr, nchar, strsplit;  
further, cat which concatenates and writes to a file, and sprintf for  
C like string construction.

See Also
paste for the reverse, grep and sub for string search and  
manipulation; further nchar, substr.

You might look at the results of:

help.search("string")

help.search("character")
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Start with

?grep

and then follow the "See Also".  Exactly what type of serious parsing
are you trying to do?  R can do some, but if it is very complex, you
might want to consider awk/perl.
On Sun, Sep 14, 2008 at 1:53 PM, zubin <binabina at bellsouth.net> wrote:

  
    
#
Try this:

 help.search(keyword = "character", package = "base")

Then read each of the pages listed to get info on the indicated command
plus related commands also described on those pages (but not necessarily
listed in the help.search list).

You might also want to look at the gsubfn package and its vignette (i.e. its pdf
document).  The gsubfn and strapply commands in that package can be used for
certain parsing tasks.  Its home page is at:
http://gsubfn.googlecode.com
On Sun, Sep 14, 2008 at 1:53 PM, zubin <binabina at bellsouth.net> wrote:
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On Sep 14, 2008, at 1:53 PM, zubin wrote:

            
A further thought would be to look at the Natural Language Processing  
TaskView:

http://cran.r-project.org/web/views/NaturalLanguageProcessing.html
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Hello, what's the most efficient way of using R to automate a data 
collection task i have:

-Login into a web site using my ID and PWD
-submit a query within the site using the search form after login
-extract the result of the search data into R so i can cleanse and use 
for analysis

kind of like a web scraping task, but like to do this in R.   I checked 
out RCurl, this seems very low level?

This leads to using R to perform mashups of various sites for data 
analysis. 

-zubin