ramsort: Generics for in-RAM sorting and ordering

Description Usage Arguments Details Value Index of implemented methods Note Author(s) See Also

View source: R/generics.R

Description

These are generic stubs for low-level sorting and ordering methods implemented in packages 'bit64' and 'ff'. The ..sortorder methods do sorting and ordering at once, which requires more RAM than ordering but is (almost) as fast as as sorting.

Usage

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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

...

further arguments to the sorting methods

Details

The sort generics do sort their argument 'x', some methods need temporary RAM of the same size as 'x'. The order generics do order their argument 'i' leaving 'x' as it was, some methods need temporary RAM of the same size as 'i'. The sortorder generics do sort their argument 'x' and order their argument 'i', this way of ordering is much faster at the price of requiring temporary RAM for both, 'x' and 'i', if the method requires temporary RAM. The ram generics are high-level functions containing an optimizer that chooses the 'best' algorithms given some context.

Value

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

Index of implemented methods

generic ff bit64
ramsort ramsort.default ramsort.integer64
shellsort shellsort.default shellsort.integer64
quicksort quicksort.integer64
mergesort mergesort.default mergesort.integer64
radixsort radixsort.default radixsort.integer64
keysort keysort.default
generic ff bit64
ramorder ramorder.default ramorder.integer64
shellorder shellorder.default shellorder.integer64
quickorder quickorder.integer64
mergeorder mergeorder.default mergeorder.integer64
radixorder radixorder.default radixorder.integer64
keyorder keyorder.default
generic ff bit64
ramsortorder ramsortorder.integer64
shellsortorder shellsortorder.integer64
quicksortorder quicksortorder.integer64
mergesortorder mergesortorder.integer64
radixsortorder radixsortorder.integer64
keysortorder

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 rationale behind this is that sorting is very RAM-intensive and in certain situations we might not want to allocate additional memory if not necessary to do so. The sort-methods change x, the order-methods change i, and the sortoder-methods change both x and i You as the user are responsible to create copies of the input data 'x' and 'i' if you need non-modified versions.

Author(s)

Jens Oehlschl<c3><a4>gel <[email protected]>

See Also

sort and order in base R


OHDSI/bit documentation built on May 9, 2017, 3:30 p.m.