gzfile() produces large files
I would guess that this is an artifact of compressionalogor.: under a unix shell: > cat tmp1.txt 1 2 3 > ls -l tmp1.txt -rw------- 1 y0004379 users 5 Juni 27 17:31 tmp1.txt > gzip tmp1.txt > ls -l tmp1.txt.gz -rw------- 1 y0004379 users 34 Juni 27 17:31 tmp1.txt.gz #####on windows r-1.3.0:
x <- rnorm(10000)
write(x, file = "c:/temp.txt")
system("ls -l c:/temp/temp.txt",T)
[1] "a----- 4093 27-Jun-101 16:50 c:/temp/temp.txt"
my.con <- gzfile("c:/temp/temp.gz", open = "w")
write(x, file = my.con)
close(my.con)
system("ls -l c:/temp/temp.gz",T)
[1] "a----- 193200 27-Jun-101 17:24 c:/temp/temp.gz" on large file the gzip - alogorithm is effective! Peter
> ls -l tmp1.txt.bz2 -rw------- 1 y0004379 users 43 Juni 27 17:31 tmp1.txt.bz2 >
On Wed, Jun 27, 2001 at 03:11:37PM +0100, Prof Brian D Prof Brian D Ripley wrote:
On Wed, 27 Jun 2001, Uwe Ligges wrote:
I observed some strange results playing around with gzfile() [R-1.3.0,
WinNT 4.0]:
At first
x <- 1:1000
write(x, file = "c:/temp.txt")
results in a file of about 4 kB. But
my.con <- gzfile("c:/temp.gz", open = "w")
write(x, file = my.con)
close(my.con)
results in a file of about 16 kB.
I expected a reduction of the size. Anyone who can tell me what went
wrong?
My experiments concur: I do get a 15913 byte file and it is a valid gzip file. I've used this much more to read compressed files than write them. I will take a closer look at the zlib specs when I have time. Brian -- 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 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
P.Malewski, Limmerstr.47, 30451 Hannover, 0511-2135008 At work: http://www.MH-Hannover.de 0511 532 3194 / Fax: 0511 532 3190, P.Malewski at tu-bs.de, peter.malewski at gmx.de, malewski.peter at mh-hannover.de. -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._