Writing to a file

Would the following do?

x <- 1000
write.table(Info[Info[,4] > x, c(1, 4)], file="/tmp/CT.dat")

Andy
From: Melanie Vida

Here is a simple question. Is there a quicker way to write to a file 
several rows of data at a time rather than one line at a 
time? How can 
the code below be optimized to write several rows at a time to a file 
rather than one line at a time. See my slow method of 
write.table below:

---------------------------
x<-1000
for( i in 1:385420)
    (
    if(Info[i,4] > x)
       write.table (cbind(Info[i,1], Info[i,4], file="/tmp/CT.dat", 
append=TRUE, row.names=FALSE, col.names=FALSE)

Thanks,

-Melanie

______________________________________________
R-help at stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! 
http://www.R-project.org/posting-guide.html

Would the following do?

x <- 1000
write.table(Info[Info[,4] > x, c(1, 4)], file="/tmp/CT.dat")

Andy

From: Melanie Vida

Here is a simple question. Is there a quicker way to write to a file
several rows of data at a time rather than one line at a
time? How can
the code below be optimized to write several rows at a time to a file
rather than one line at a time. See my slow method of
write.table below:
There is almost no penalty in writing a line at a time *if* you open a 
connection and write to that.  It might save you if Andy's solution runs 
you out of memory.  I would investigate doing this is large blocks of rows 
in that case.
---------------------------
x<-1000
for( i in 1:385420)
    (
    if(Info[i,4] > x)
       write.table (cbind(Info[i,1], Info[i,4], file="/tmp/CT.dat",
append=TRUE, row.names=FALSE, col.names=FALSE)

Thanks,

-Melanie

______________________________________________
R-help at stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html

______________________________________________
R-help at stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html

Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595
Yes, Andy, the command you gave takes only a minute to output the whole 
data set to a file rather than mine, which takes hours to complete the 
file ouput operation. Thanks!

Would the following do?

x <- 1000
write.table(Info[Info[,4] > x, c(1, 4)], file="/tmp/CT.dat")

Andy

From: Melanie Vida

Here is a simple question. Is there a quicker way to write to a file 
several rows of data at a time rather than one line at a 
time? How can 
the code below be optimized to write several rows at a time to a file 
rather than one line at a time. See my slow method of 
write.table below:

---------------------------
x<-1000
for( i in 1:385420)
   (
   if(Info[i,4] > x)
      write.table (cbind(Info[i,1], Info[i,4], file="/tmp/CT.dat", 
append=TRUE, row.names=FALSE, col.names=FALSE)

Thanks,

-Melanie

______________________________________________
R-help at stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! 
http://www.R-project.org/posting-guide.html

------------------------------------------------------------------------------
Notice:  This e-mail message, together with any attachments, contains information of Merck & Co., Inc. (One Merck Drive, Whitehouse Station, New Jersey, USA 08889), and/or its affiliates (which may be known outside the United States as Merck Frosst, Merck Sharp & Dohme or MSD and in Japan, as Banyu) that may be confidential, proprietary copyrighted and/or legally privileged. It is intended solely for the use of the individual or entity named on this message.  If you are not the intended recipient, and have received this message in error, please notify us immediately by reply e-mail and then delete it from your system.
------------------------------------------------------------------------------