[R] memory problem in exporting data frame

[array chip]

Patrick,

Thanks for the suggestion. do you mean you need to
change each row of the data frame into a text string
using something like "paste(data[1,],collapse='\t')"
and then output the resulting character vector into a
file using writeLines?

It seems not working with my data mainly because my
data is in a data frame, not in a matrix. even a
single operation like "data[1,]" takes tremendous time
to complete (I think it will be much easier and faster
if my data is in a matrix).

If anyone has suggestions, I would appreciate letting
me know.

Thanks anyway.


--- Patrick Burns <pburns at pburns.seanet.com> wrote:
> I had a similar problem not long ago.  My solution
> was to
> look at the definition of "write.table" and
> essentially do it
> by hand.  The key steps are to create a matrix of
> characters
> that includes the dimnames (if desired), and then
> use
> "writeLines" to put that into a file.
> 
> My machine has 1G as well and my problem was a
> numeric
> matrix that was 5000 square.  So you should have no
> problem.
> 
> Patrick Burns
> 
> Burns Statistics
> patrick at burns-stat.com
> +44 (0)20 8525 0696
> http://www.burns-stat.com
> (home of S Poetry and "A Guide for the Unwilling S
> User")
> 
> array chip wrote:
> 
> >Hi,
> >
> >I am having trouble of exporting a large data frame
> >out of R to be used in other purpose. The data
> frame
> >is numeric with size 17000x400. It takes a quite
> some
> >time to start R as well. my computer has 1GB RAM. I
> >used the following command to write the data frame
> to
> >a text file and got the error message below:
> >
> >  
> >
> >>write.table(xxx, "C:\\xxx", sep="\t",
> >>    
> >>
> >row.names=FALSE,col.names=FALSE,quote=FALSE)
> >
> >Error: cannot allocate vector of size 55750 Kb
> >In addition: Warning message: 
> >Reached total allocation of 1023Mb: see
> >help(memory.size) 
> >
> >I tried to increase the memory size by
> >memory.size(size=), but it seems running the above
> >command takes forever.
> >
> >what can I do with this error message to get the
> data
> >out? 
> >
> >Thanks
> >
> >______________________________________________
> >R-help at stat.math.ethz.ch mailing list
>
>https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> >
> >
> >  
> >
> 
>