Maybe you can make a package for something like this. (IP sort,etc). Like in
Perl, there is a module called Sort::Key::IPv4
I think, not only me has the same problem for sorting e.g IP?
Eddie
> Not really, just the old saying that any piece of code can be made
> twice as fast (which often holds true recursively). /Henrik
>
> On Sun, May 31, 2009 at 1:58 PM, Wacek Kusnierczyk
>
> <waclaw.marcin.kusnierc...@idi.ntnu.no> wrote:
> > wow! :)
> >
> > vQ
> >
> > Henrik Bengtsson wrote:
> >> library(gsubfn)
> >> library(gtools)
> >> library(rbenchmark)
> >>
> >> n <- 10000
> >> df <- data.frame(
> >> a = rnorm(n),
> >> b = rnorm(n),
> >> c = rnorm(n),
> >> ip = replicate(n, paste(sample(255, 4), collapse='.'), simplify=TRUE)
> >> )
> >>
> >> res <- benchmark(columns=c('test', 'elapsed'), replications=10,
> >> order=NULL, peda = {
> >> connection <- textConnection(as.character(df$ip))
> >> o <- do.call(order, read.table(connection, sep='.'))
> >> close(connection)
> >> df[o, ]
> >> },
> >>
> >> peda2 = {
> >> connection <- textConnection(as.character(df$ip))
> >> dfT <- read.table(connection, sep='.', colClasses=rep("integer",
> >> 4), quote="", na.strings=NULL, blank.lines.skip=FALSE)
> >> close(connection)
> >> o <- do.call(order, dfT)
> >> df[o, ]
> >> },
> >>
> >> hb = {
> >> ip <- strsplit(as.character(df$ip), split=".", fixed=TRUE)
> >> ip <- unlist(ip, use.names=FALSE)
> >> ip <- as.integer(ip)
> >> dim(ip) <- c(4, nrow(df))
> >> ip <- 256^3*ip[1,] + 256^2*ip[2,] + 256*ip[3,] + ip[4,]
> >> o <- order(ip)
> >> df[o, ]
> >> },
> >>
> >> hb2 = {
> >> ip <- strsplit(as.character(df$ip), split=".", fixed=TRUE)
> >> ip <- unlist(ip, use.names=FALSE)
> >> ip <- as.integer(ip);
> >> dim(ip) <- c(4, nrow(df))
> >> o <- sort.list(ip[4,], method="radix", na.last=TRUE)
> >> for (kk in 3:1) {
> >> o <- o[sort.list(ip[kk,o], method="radix", na.last=TRUE)]
> >> }
> >> df[o, ]
> >> }
> >> )
> >>
> >> print(res)
> >>
> >> test elapsed
> >> 1 peda 4.12
> >> 2 peda2 4.08
> >> 3 hb 0.28
> >> 4 hb2 0.25
> >
> > ______________________________________________
> > R-help@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html and provide commented,
> > minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html and provide commented, minimal,
> self-contained, reproducible code.
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