sortnut: Searching and other uses of sorting for 64bit integers

In bit64: A S3 Class for Vectors of 64bit Integers

Searching and other uses of sorting for 64bit integers

Description

This is roughly an implementation of hash functionality but based on sorting instead on a hasmap. Since sorting is more informative than hashingwe can do some more interesting things.

Usage

sortnut(sorted, ...)
ordernut(table, order, ...)
sortfin(sorted, x, ...)
orderfin(table, order, x, ...)
orderpos(table, order, x, ...)
sortorderpos(sorted, order, x, ...)
orderdup(table, order, ...)
sortorderdup(sorted, order, ...)
sortuni(sorted, nunique, ...)
orderuni(table, order, nunique, ...)
sortorderuni(table, sorted, order, nunique, ...)
orderupo(table, order, nunique, ...)
sortorderupo(sorted, order, nunique, keep.order = FALSE, ...)
ordertie(table, order, nties, ...)
sortordertie(sorted, order, nties, ...)
sorttab(sorted, nunique, ...)
ordertab(table, order, nunique, ...)
sortordertab(sorted, order, ...)
orderkey(table, order, na.skip.num = 0L, ...)
sortorderkey(sorted, order, na.skip.num = 0L, ...)
orderrnk(table, order, na.count, ...)
sortorderrnk(sorted, order, na.count, ...)
## S3 method for class 'integer64'
sortnut(sorted, ...)
## S3 method for class 'integer64'
ordernut(table, order, ...)
## S3 method for class 'integer64'
sortfin(sorted, x, method=NULL, ...)
## S3 method for class 'integer64'
orderfin(table, order, x, method=NULL, ...)
## S3 method for class 'integer64'
orderpos(table, order, x, nomatch=NA, method=NULL, ...)
## S3 method for class 'integer64'
sortorderpos(sorted, order, x, nomatch=NA, method=NULL, ...)
## S3 method for class 'integer64'
orderdup(table, order, method=NULL, ...)
## S3 method for class 'integer64'
sortorderdup(sorted, order, method=NULL, ...)
## S3 method for class 'integer64'
sortuni(sorted, nunique, ...)
## S3 method for class 'integer64'
orderuni(table, order, nunique, keep.order=FALSE, ...)
## S3 method for class 'integer64'
sortorderuni(table, sorted, order, nunique, ...)
## S3 method for class 'integer64'
orderupo(table, order, nunique, keep.order=FALSE, ...)
## S3 method for class 'integer64'
sortorderupo(sorted, order, nunique, keep.order = FALSE, ...)
## S3 method for class 'integer64'
ordertie(table, order, nties, ...)
## S3 method for class 'integer64'
sortordertie(sorted, order, nties, ...)
## S3 method for class 'integer64'
sorttab(sorted, nunique, ...)
## S3 method for class 'integer64'
ordertab(table, order, nunique, denormalize=FALSE, keep.order=FALSE, ...)
## S3 method for class 'integer64'
sortordertab(sorted, order, denormalize=FALSE, ...)
## S3 method for class 'integer64'
orderkey(table, order, na.skip.num = 0L, ...)
## S3 method for class 'integer64'
sortorderkey(sorted, order, na.skip.num = 0L, ...)
## S3 method for class 'integer64'
orderrnk(table, order, na.count, ...)
## S3 method for class 'integer64'
sortorderrnk(sorted, order, na.count, ...)
## S3 method for class 'integer64'
sortqtl(sorted, na.count, probs, ...)
## S3 method for class 'integer64'
orderqtl(table, order, na.count, probs, ...)

Arguments

x	an integer64 vector
sorted	a sorted integer64 vector
table	the original data with original order under the sorted vector
order	an integer order vector that turns 'table' into 'sorted'
nunique	number of unique elements, usually we get this from cache or call sortnut or ordernut
nties	number of tied values, usually we get this from cache or call sortnut or ordernut
denormalize	FALSE returns counts of unique values, TRUE returns each value with its counts
nomatch	the value to be returned if an element is not found in the hashmap
keep.order	determines order of results and speed: FALSE (the default) is faster and returns in sorted order, TRUE returns in the order of first appearance in the original data, but this requires extra work
probs	vector of probabilities in [0..1] for which we seek quantiles
na.skip.num	0 or the number of NAs. With 0, NAs are coded with 1L, with the number of NAs, these are coded with NA, the latter needed for as.factor.integer64
na.count	the number of NAs, needed for this low-level function algorithm
method	see details
...	further arguments, passed from generics, ignored in methods

Details

sortfun	orderfun	sortorderfun	see also	description
sortnut	ordernut			return number of tied and of unique values
sortfin	orderfin		%in%.integer64	return logical whether x is in table
	orderpos	sortorderpos	match	return positions of x in table
	orderdup	sortorderdup	duplicated	return logical whether values are duplicated
sortuni	orderuni	sortorderuni	unique	return unique values (=dimensiontable)
	orderupo	sortorderupo	unique	return positions of unique values
	ordertie	sortordertie		return positions of tied values
	orderkey	sortorderkey		positions of values in vector of unique values (match in dimensiontable)
sorttab	ordertab	sortordertab	table	tabulate frequency of values
	orderrnk	sortorderrnk		rank averaging ties
sortqtl	orderqtl			return quantiles given probabilities

The functions sortfin, orderfin, orderpos and sortorderpos each offer three algorithms for finding x in table.
With method=1L each value of x is searched independently using binary search, this is fastest for small tables.
With method=2L the values of x are first sorted and then searched using doubly exponential search, this is the best allround method.
With method=3L the values of x are first sorted and then searched using simple merging, this is the fastest method if table is huge and x has similar size and distribution of values.
With method=NULL the functions use a heuristic to determine the fastest algorithm.

The functions orderdup and sortorderdup each offer two algorithms for setting the truth values in the return vector.
With method=1L the return values are set directly which causes random write access on a possibly large return vector.
With method=2L the return values are first set in a smaller bit-vector – random access limited to a smaller memory region – and finally written sequentially to the logical output vector.
With method=NULL the functions use a heuristic to determine the fastest algorithm.

Value

see details

Author(s)

Jens Oehlschlägel <[e-mail]>

See Also

match

Examples

 message("check the code of 'optimizer64' for examples:")
 print(optimizer64)

bit64 documentation built on Sept. 30, 2024, 9:23 a.m.