bit64: ramsort.integer64 – R documentation

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ramsort.integer64

Low-level intger64 methods for in-RAM sorting and ordering

Description

Fast low-level methods for sorting and ordering. The ..sortorder methods do sorting and ordering at once, which requires more RAM than ordering but is (almost) as fast as as sorting.

Usage

## S3 method for class 'integer64'
shellsort(x, has.na=TRUE, na.last=FALSE, decreasing=FALSE, ...)
## S3 method for class 'integer64'
shellsortorder(x, i, has.na=TRUE, na.last=FALSE, decreasing=FALSE, ...)
## S3 method for class 'integer64'
shellorder(x, i, has.na=TRUE, na.last=FALSE, decreasing=FALSE, ...)
## S3 method for class 'integer64'
mergesort(x, has.na=TRUE, na.last=FALSE, decreasing=FALSE, ...)
## S3 method for class 'integer64'
mergeorder(x, i, has.na=TRUE, na.last=FALSE, decreasing=FALSE, ...)
## S3 method for class 'integer64'
mergesortorder(x, i, has.na=TRUE, na.last=FALSE, decreasing=FALSE, ...)
## S3 method for class 'integer64'
quicksort(x, has.na=TRUE, na.last=FALSE, decreasing=FALSE
, restlevel=floor(1.5*log2(length(x))), ...)
## S3 method for class 'integer64'
quicksortorder(x, i, has.na=TRUE, na.last=FALSE, decreasing=FALSE
, restlevel=floor(1.5*log2(length(x))), ...)
## S3 method for class 'integer64'
quickorder(x, i, has.na=TRUE, na.last=FALSE, decreasing=FALSE
, restlevel=floor(1.5*log2(length(x))), ...)
## S3 method for class 'integer64'
radixsort(x, has.na=TRUE, na.last=FALSE, decreasing=FALSE, radixbits=8L, ...)
## S3 method for class 'integer64'
radixsortorder(x, i, has.na=TRUE, na.last=FALSE, decreasing=FALSE, radixbits=8L, ...)
## S3 method for class 'integer64'
radixorder(x, i, has.na=TRUE, na.last=FALSE, decreasing=FALSE, radixbits=8L, ...)
## S3 method for class 'integer64'
ramsort(x, has.na = TRUE, na.last=FALSE, decreasing = FALSE, stable = TRUE
, optimize = c("time", "memory"), VERBOSE = FALSE, ...)
## S3 method for class 'integer64'
ramsortorder(x, i, has.na = TRUE, na.last=FALSE, decreasing = FALSE, stable = TRUE
, optimize = c("time", "memory"), VERBOSE = FALSE, ...)
## S3 method for class 'integer64'
ramorder(x, i, has.na = TRUE, na.last=FALSE, decreasing = FALSE, stable = TRUE
, optimize = c("time", "memory"), VERBOSE = FALSE, ...)

Arguments

`x`	a vector to be sorted by `ramsort` and `ramsortorder`, i.e. the output of `sort`
`i`	integer positions to be modified by `ramorder` and `ramsortorder`, default is 1:n, in this case the output is similar to `order`
`has.na`	boolean scalar defining whether the input vector might contain `NA`s. If we know we don't have NAs, this may speed-up. Note that you risk a crash if there are unexpected `NA`s with `has.na=FALSE`
`na.last`	boolean scalar telling ramsort whether to sort `NA`s last or first. Note that 'boolean' means that there is no third option `NA` as in `sort`
`decreasing`	boolean scalar telling ramsort whether to sort increasing or decreasing
`stable`	boolean scalar defining whether stable sorting is needed. Allowing non-stable may speed-up.
`optimize`	by default ramsort optimizes for 'time' which requires more RAM, set to 'memory' to minimize RAM requirements and sacrifice speed
`restlevel`	number of remaining recursionlevels before `quicksort` switches from recursing to `shellsort`
`radixbits`	size of radix in bits
`VERBOSE`	cat some info about chosen method
`...`	further arguments, passed from generics, ignored in methods

Details

see ramsort

Value

These functions return the number of NAs found or assumed during sorting

Note

Note that these methods purposely violate the functional programming paradigm: they are called for the side-effect of changing some of their arguments. The sort-methods change x, the order-methods change i, and the sortoder-methods change both x and i

Author(s)

Jens Oehlschlägel <Jens.Oehlschlaegel@truecluster.com>

Examples

x <- as.integer64(sample(c(rep(NA, 9), 1:9), 32, TRUE))
  x
  message("ramsort example")
  s <- clone(x)
  ramsort(s)
  message("s has been changed in-place - whether or not ramsort uses an in-place algorithm")
  s
  message("ramorder example")
  s <- clone(x)
  o <- seq_along(s)
  ramorder(s, o)
  message("o has been changed in-place - s remains unchanged")
  s
  o
  s[o]
  message("ramsortorder example")
  o <- seq_along(s)
  ramsortorder(s, o)
  message("s and o have both been changed in-place - this is much faster")
  s
  o

bit64

A S3 Class for Vectors of 64bit Integers

v4.0.5

GPL-2 | GPL-3

Authors

Jens Oehlschlägel [aut, cre], Leonardo Silvestri [ctb]

Initial release

2020-08-29