[R] IP-Address

[Wacek Kusnierczyk]

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
>