Fast parallel sort — fsort • data.table

Similar to base::sort but fast using parallelism. Experimental.

Usage

fsort(x, decreasing = FALSE, na.last = FALSE, internal=FALSE, verbose=FALSE, ...)

Arguments

x: A vector. Type double, currently.
decreasing: Decreasing order?
na.last: Control treatment of NAs. If TRUE, missing values in the data are put last; if FALSE, they are put first; if NA, they are removed; if "keep" they are kept with rank NA.
internal: Internal use only. Temporary variable. Will be removed.
verbose: Print tracing information.
...: Not sure yet. Should be consistent with base R.

Details

Process will raise error if x contains negative values. Unless x is already sorted fsort will redirect processing to slower single threaded order followed by subset in following cases:

data type other than double (numeric)
data having NAs
decreasing==FALSE

Value

The input in sorted order.

Examples

x = runif(1e6)
system.time(ans1 <- sort(x, method="quick"))
#>    user  system elapsed 
#>   0.107   0.003   0.109 
system.time(ans2 <- fsort(x))
#>    user  system elapsed 
#>   0.032   0.004   0.019 
identical(ans1, ans2)
#> [1] TRUE