Hits-setops {S4Vectors} | R Documentation

## Set operations on Hits objects

### Description

Perform set operations on Hits objects.

### Details

`union(x, y)`, `intersect(x, y)`, `setdiff(x, y)`, and `setequal(x, y)` work on Hits objects `x` and `y` only if the objects are compatible Hits objects, that is, if they have the same subject and query lengths. These operations return respectively the union, intersection, (asymmetric!) difference, and equality of the sets of hits in `x` and `y`.

### Value

`union` returns a Hits object obtained by appending to `x` the hits in `y` that are not already in `x`.

`intersect` returns a Hits object obtained by keeping only the hits in `x` that are also in `y`.

`setdiff` returns a Hits object obtained by dropping from `x` the hits that are in `y`.

`setequal` returns `TRUE` if `x` and `y` contain the same sets of hits and `FALSE` otherwise.

`union`, `intersect`, and `setdiff` propagate the names and metadata columns of their first argument (`x`).

### Author(s)

Hervé Pagès and Michael Lawrence

### See Also

- Hits objects.

- Hits-comparison for comparing and ordering hits.

- `BiocGenerics::union`, `BiocGenerics::intersect`, and `BiocGenerics::setdiff` in the BiocGenerics package for general information about these generic functions.

### Examples

    x <- Hits(c(2, 4, 4, 4, 5, 5), c(3, 1, 3, 2, 3, 2), 6, 3,
              score=11:16)
    x

    y <- Hits(c(1, 3, 4, 4, 5, 5, 5), c(3, 3, 2, 1, 2, 1, 3), 6, 3,
              score=21:27)
    y

    union(x, y)
    union(y, x)  # same hits as in union(x, y), but in different order

    intersect(x, y)
    intersect(y, x)  # same hits as in intersect(x, y), but in
                     # different order

    setdiff(x, y)
    setdiff(y, x)

    setequal(x, y)

[Package S4Vectors version 0.22.1 Index]