[R] Writing out data

[R. Michael Weylandt]

I believe connections were designed to do this as efficiently as
possible by keeping the i/o path "open" rather than reopening it each
time like write.table(append = TRUE) would do, though I may be wrong
on the details: see ?connections. Prof Ripley has a good article about
them in R News 1.1 --
http://cran.r-project.org/doc/Rnews/Rnews_2001-1.pdf -- but it's a
rather out of date.

Michael

On Thu, Feb 2, 2012 at 7:56 AM, Ivan Calandra
<ivan.calandra at u-bourgogne.fr> wrote:
> Correct me if I'm wrong, but I think that write.csv() doesn't have an append
> argument; write.table() does though.
>
> Ivan
>
> --
> Ivan CALANDRA
> Université de Bourgogne
> UMR CNRS/uB 6282 Biogéosciences
> 6 Boulevard Gabriel
> 21000 Dijon, FRANCE
> +33(0)3.80.39.63.06
> ivan.calandra at u-bourgogne.fr
>
>
> Le 02/02/12 13:43, Paul Hiemstra a écrit :
>
>> On 02/02/2012 11:40 AM, Thomas wrote:
>>>
>>> What is the best way to write out comma separated data, as a program
>>> is running (rather than waiting to the end using write.csv)? At the
>>> moment I'm doing this, but I guess it's not the most efficient. The
>>> data is in a column in the matrix postcount, and I'm using a loop to
>>> write out each of the 100 elements.
>>>
>>> for (j in 1:100)
>>> {
>>> cat(postcount[1,j], ",", file=filename, append=TRUE)
>>> }
>>> cat("\n", file=filename, append=TRUE)
>>>
>>>
>>> Thank you!
>>>
>>> Thomas
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>>
>> Hi,
>>
>> write.csv also supports an append argument. Maybe that is faster than
>> using cat.
>>
>> cheers,
>> Paul
>>
>
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