On Mon, 15 Dec 2008, megh wrote:
Thanks Charles for this reply. I have started according to your suggestion
and hopefully I can do it. In the mean time what I was thinking, instead of
calling my text files by their names, is there any mechanism to call them by
the order they are stored in that directory?
I am not sure what that order would be. If you mean 'how would I order
files by (say) creation date?', see
?file.info
Eventually you need a string that has the file name in it or a connection
object (see ?connection) that accesses the file(s).
Means, suppose, I have total
1000 text files in that directory and therefore I create a vector like
sel.no <- c(1:1000). Next I use the i-th element of the vector "sel.no" to
access the i-th file?
Hmmm. Something about this question is telling me you are either a novice
programmer or really unfamiliar with R or perhaps you just need that extra
cup of coffee.
In any but the latter case, let me suggest that it helps to reread the
Intro to R (and any other books/manuals you might have), read help pages
for possibly relevant functions, and to run example( file.info ), say, to
get a handle on functions you are tying to learn. Also, rereading the
_posting guide_ is helpful as it is, in part, a guide to figuring out
things in R.
HTH,
Chuck
With regards,
Charles C. Berry wrote:
On Mon, 15 Dec 2008, megh wrote:
Hi all,
I my c: drive I have possibly 1,000 notepad files, with .txt extension.
They
are named as the dates on which they were saved i.e. 1st file name is
"Volume_4-18-2008", 2nd one is "Volume_4-21-2008", 3rd one
"Volume_4-22-2008" and so on............
Also, content of each file are in same format like :
******** content of 1st file *************
section : 1
----- --------- ---------- -----------
----- --------- ---------- -----------
----- --------- ---------- -----------
----- --------- ---------- -----------
section : 2
----- --------- ---------- -----------
----- --------- ---------- -----------
----- --------- ---------- -----------
----- --------- ---------- -----------
section : 3
----- --------- ---------- -----------
----- --------- ---------- -----------
----- --------- ---------- -----------
----- --------- ---------- -----------
section : 4
----- --------- ---------- -----------
----- --------- ---------- -----------
----- --------- ---------- -----------
----- --------- ---------- -----------
Here all files have 4-sections, just like shown here but contents within
each section (i.e. dashed line here) differs file to file.
What I have to do is I have to fetch contents of "section : 2" from each
file and then save it to a R-object, matrix of list for further analysis.
Can you ppl please tell me how to do that?
Here is the outline:
*) use list.files() or Sys.glob() to get a list of the files
*) write a function that takes the file name as its arg, uses
readLines() to swallow the text and uses grep() to find the
'section' lines. Then put the 'dashes' in between two section
lines into a separate object (say, dash.lines). Then use
as.matrix( read.table(con <- textConnection( dash.lines ) )
close(con)
to get the numeric values or maybe
sapply( strsplit(dash.lines, "[ ]+"), as.numeric)
*) debug this on one file
*) use lapply to step thru the list of file names.
See
?list.files
?Sys.glob
?readLines
?grep
?textConnection
?strsplit
?sapply
HTH,
Chuck
Thanks and regards,
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______________________________________________
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PLEASE do read the posting guide
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Charles C. Berry (858) 534-2098
Dept of Family/Preventive
Medicine
E mailto:cbe...@tajo.ucsd.edu UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/ La Jolla, San Diego 92093-0901
______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
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______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Charles C. Berry (858) 534-2098
Dept of Family/Preventive Medicine
E mailto:cbe...@tajo.ucsd.edu UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/ La Jolla, San Diego 92093-0901
______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
