set_operations: Set operations
In nanotime: Nanosecond-Resolution Time Support for R

intersect,nanoival,nanoival-method

R Documentation

Set operations

Description

Performs set intersection, union and difference between vectors of temporal types from the nanotime package.

Usage

## S4 method for signature 'nanoival,nanoival'
intersect(x, y)

## S4 method for signature 'nanoival,nanoival'
union(x, y)

## S4 method for signature 'nanoival,nanoival'
setdiff(x, y)

## S4 method for signature 'nanotime,nanoival'
intersect.idx(x, y)

## S3 method for class 'nanotime'
x %in% table

## S4 method for signature 'nanotime,nanoival'
x %in% table

## S4 method for signature 'nanotime,nanoival'
intersect(x, y)

## S4 method for signature 'nanotime,nanoival'
setdiff(x, y)

## S4 method for signature 'nanotime,nanoival'
setdiff.idx(x, y)

## S4 method for signature 'nanotime,nanotime'
intersect(x, y)

## S4 method for signature 'nanotime,nanotime'
union(x, y)

## S4 method for signature 'nanotime,nanotime'
setdiff(x, y)

Arguments

`x`, `y`	a temporal type
`table`	`nanoival`: used in `%in%`

Details

Set operations between nanoival operands allow the construction of complex interval vectors (i.e. a nanoival vector can specify any number of inclusions and exclusions of time). Set operations between nanotime and nanoival allow to subset time vectors with interval vectors. In addition to the generic set functions, the function intersect.idx is defined which returns the indices of the intersection, and the operator %in% is overloaded for nanotime-nanoival which returns a logical vector that indicates which elements belong to the interval vector.

Value

intersect, union, setdiff return temporal types that are the result of the intersection. For instance, set operations on two nanoival return a nanoival, whereas intersection between a nanoival and a nanotime returns a nanotime. intersect.idx return a list of vectors representing the element indices that intersect and setdiff.idx returns a vector representing the element indices to be removed.

Examples

## Not run: 
## a vector of 'nanotime' can be subsetted by a 'nanoival' which is equivalent to 'intersect':
one_second <- 1e9
a <- seq(nanotime("2012-12-12 12:12:12+00:00"), length.out=10, by=one_second)
idx <- c(as.nanoival("-2012-12-12 12:12:10+00:00 -> 2012-12-12 12:12:14+00:00-"),
         as.nanoival("+2012-12-12 12:12:18+00:00 -> 2012-12-12 12:12:20+00:00+"))
a[idx]
intersect(a, idx)

## 'nanoival' also has the set operations 'union', 'intersect', 'setdiff':
a <- seq(nanotime("2012-12-12 12:12:12+00:00"), length.out=10, by=one_second)
i <- as.nanoival("-2012-12-12 12:12:14+00:00 -> 2012-12-12 12:12:18+00:00-")
setdiff(a, i)

i1 <- as.nanoival("+2012-12-12 12:12:14+00:00 -> 2012-12-12 12:12:17+00:00-")
i2 <- as.nanoival("+2012-12-12 12:12:16+00:00 -> 2012-12-12 12:12:18+00:00-")
union(i1, i2)

## 'intersect.idx' returns the indices of the intersection:
a <- seq(nanotime("2012-12-12 12:12:12+00:00"), length.out=10, by=one_second)
idx <- as.nanoival("+2012-12-12 12:12:14+00:00 -> 2012-12-12 12:12:19+00:00+")
idx_intersect <- intersect.idx(a, idx)

## Intersection can be performed using these indices:
a[idx_intersect$x]

## which is equivalent to:
a[idx]

## The logical vector indicating intersection can be obtained like this:
a %in% idx

## End(Not run)

nanotime documentation built on Sept. 30, 2024, 9:44 a.m.