On Fri, 26-Feb-2010 at 12:15AM -0800, Madhavi Bhave wrote:
|> Dear R helpers
|> ?
|> Some particular analysis leads me to various number of output csv
|> files depending on some conditions. Say e.g. I have output files
|> variable1.csv, variable2.csv, .............. Problem is I don't
|> know how many csv files been generated. They could be 4, 5 or even
|> 10. Each file will have a column called amount. ?
|> My problem is to find filewise mean(amount) and sd(amount). I need
|> to write a loop where all these individual csv files will be read
|> and after reading each file, mean and sd will be calculated. ?
|> I have tried to write some R code which is very absurd.
|> ?
|> for (i in 1 : n)? # n is no of input files
There's a bit of a problem with your character encoding. On my
system, I get that question mark which doesn't make syntactic sense.
Just what you have there, I can't guess, so it's a bit hard to work
out what could be the problem (apart from not knowing what size n
should be).
|> ?
|> {
|> data[i] = read.csv(file = paste("variable", i, ".csv", sep = ""))$amount
|> mean(data[i])
|> sd(data[i])
You'll need to tell us what your object 'data' is. You probably need a
list, in which case data[[i]] might work.
|> }
|> ?
|> I get following error.
|> ?
|> Error in file(file, "rt") : cannot open the connection
|> In addition: Warning message:
|> In file(file, "rt") :
|> ? cannot open file 'paste("output", i, ".csv", sep = "")': Invalid argument
|>
|> ?
|> Please guide
The posting guide might have given you a few ideas. We don't know
what you did that used "output" in it to have any idea what could be
behind the Invalid argument message.
|> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
HTH
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_( Y )_ Average minds discuss events
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