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Writing out data

4 messages · Thomas Friedrichsmeier, Paul Hiemstra, Ivan Calandra +1 more

#
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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#
On 02/02/2012 11:40 AM, Thomas wrote:
Hi,

write.csv also supports an append argument. Maybe that is faster than
using cat.

cheers,
Paul
#
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
Universit? de Bourgogne
UMR CNRS/uB 6282 Biog?osciences
6 Boulevard Gabriel
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ivan.calandra at u-bourgogne.fr


Le 02/02/12 13:43, Paul Hiemstra a ?crit :
#
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rather out of date.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: