[R] Print to File Formatting

Luc Villandre villandl at dms.umontreal.ca
Thu May 7 15:45:42 CEST 2009

Brigid Mooney wrote:
> Hello,
> I am writing out to a file and have two quick questions that I can't
> seem to track down the correct answers for.  Luckily, I *think* they
> are both simple enough that someone might be able to point me in the
> right direction on them without too much trouble.
> Both questions relate to the process below where CompleteFrame is a
> data frame containing what I want printed to a file.
> filename <- "C:\\MyDocuments\\TestOut_050609.txt"
> output <-file(filename, open="wt")
> write.csv(CompleteFrame, output, row.names = FALSE, col.names=FALSE)
> close(output)
> Question #1:
> Every time I run this process, I get the warning:
> Warning message:
> In write.csv(CompleteFrame, output, row.names = FALSE, col.names = FALSE) :
>   attempt to set 'col.names' ignored
> And it still prints the column names as the first row in my file,
> which I do not want...
> Question #2:
> This process puts quotes around all data of class = character.
> I can't have these quotes in my file - is it possible to get R to omit
> them even if my data frame contains character strings?
> Any help or hints on this are greatly appreciated!
> Thanks,
> Brigid
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> and provide commented, minimal, self-contained, reproducible code.
Hi Brigid,

Re. Question 1: This is simply due to a convention about csv files. In 
order to ensure conformity of the output file, write.csv() doesn't allow 
users to change col.names.

Re. Question 2: The "quote" argument is what you should be modifying.

If you really want no column names, use write.table() instead (with 
sep="," and a filename with a .csv extension). After all, write.csv() is 
merely a wrapper for write.table().


*Luc Villandré*
McGill University Health Center -
Montreal Children's Hospital Research Institute/

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