[R] Faster Printing Alternatives to 'cat'

[Gundala Viswanath]

How do you do that Henrik? Write.table doesn't have that option.

Usage:
     write.table(x, file = "", append = FALSE, quote = TRUE, sep = " ",
                 eol = "\n", na = "NA", dec = ".", row.names = TRUE,
                 col.names = TRUE, qmethod = c("escape", "double"))


- Gundala Viswanath
Jakarta - Indonesia



On Sun, Jan 18, 2009 at 12:09 AM, Henrik Bengtsson <hb at stat.berkeley.edu> wrote:
> Do it in chunks of rows. /H
>
> On Sat, Jan 17, 2009 at 6:55 AM, Gundala Viswanath <gundalav at gmail.com> wrote:
>> Hi Hadley,
>>
>> I had to do it by line. Because, in practice, I will
>> manipulate the figures and string before printing it.
>>
>> And I can't bind these results into one new object,
>> because there are literally millions of this lines, and
>> R object can't handle that in my 4GB Ram memory.
>>
>> I tried your suggestion already, I have memory problem
>>
>>> x <- cbind(dat$V1, as.character(dat$V2))
>> Error: cannot allocate vector of size 4.2 Gb
>> Execution halted
>>
>> - Gundala Viswanath
>> Jakarta - Indonesia
>>
>>
>>
>> On Sat, Jan 17, 2009 at 11:39 PM, hadley wickham <h.wickham at gmail.com> wrote:
>>> On Sat, Jan 17, 2009 at 7:59 AM, gundalav <gundalav at gmail.com> wrote:
>>>> Dear Jim and all,
>>>>
>>>> Allow me to ask your expert opinion.
>>>>
>>>>
>>>> Using the data (16Mb) downloadable from here:
>>>>
>>>> http://drop.io/gundalav/asset/test-data-zip
>>>>
>>>>
>>>> It took this long under 1994.070Mhz Cpu Linux, using
>>>> "write.table"
>>>>
>>>>> proc.time() - ptm1
>>>>     user    system   elapsed
>>>> 16581.833  5787.228 21386.064
>>>>
>>>>
>>>>
>>>> __MYCODE__
>>>>
>>>> args <- commandArgs(trailingOnly=FALSE)
>>>> fname <- args[3]
>>>> dat <- read.delim(fname, header=FALSE);
>>>>
>>>> output <- file('output_writetable.txt', 'w')
>>>>
>>>>
>>>> ptm1 <- proc.time()
>>>> for (i in 1:nrow(dat)) {
>>>>
>>>>     #cat(dat$V1[i]," ", as.character(dat$V2[i]),"\n", sep="")
>>>>     write.table(cbind(dat$V1[i], as.character(dat$V2[i])),
>>>> file=output, sep="\t", quote=FALSE, col.names=FALSE, row.names=FALSE)
>>>> }
>>>>
>>>> close(output)
>>>> proc.time() - ptm1
>>>> __END__
>>>>
>>>> Perhaps I misunderstood you. But seems that this is
>>>> truly slow. Is there a way I can speed it up?
>>>
>>> Don't do it line by line!
>>>
>>> write.table(dat[, c("V1", "V2")], file='output_writetable.txt',
>>> sep="\t", quote=FALSE, col.names=FALSE, row.names=FALSE)
>>>
>>> Hadley
>>>
>>> --
>>> http://had.co.nz/
>>>
>>
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>>
>