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
>
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