[R] Faster Printing Alternatives to 'cat'

[Henrik Bengtsson]

On Thu, Jan 8, 2009 at 3:12 AM, Gundala Viswanath <gundalav at gmail.com> wrote:
> Dear all,
>
> I found that printing with 'cat' is very slow.
>
> For example in my machine this snippet
>
> __BEGIN__
>
> # I need to resolve to use this type of loop.
> # because using write(), I need to create a matrix  which
> # consumes so much memory. Note that "foo, bar, qux" object
> # is already very large (>2Gb)
>
> for ( s in 1:length(x) ) {
>    cat(as.character(foo[s]),"\t",bar[s],"\t", qux[s],"\n")
> }
> __END__
>
> for "x" of size ~1.5million, takes more than 10 hours to print.
> On my Linux 1994.MHz AMD processor.

But that's nothing compared to how long it will take you to read it.

>
> Is there any faster alternatives to "cat" ?

What are you trying to achieve?  Writing the data to file?  Something like this?

strs <- paste(as.character(foo), bar, qux, sep="\t");
writeLines(strs, con="foo.txt");

See also help(write.table) and friends.

/Henrik

>
>
> - Gundala Viswanath
> Jakarta - Indonesia
>
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