findOverlaps-methods {IRanges} | R Documentation

## Finding overlapping ranges

### Description

Various methods for finding/counting interval overlaps between two "range-based" objects: a query and a subject.

NOTE: This man page describes the methods that operate on IntegerRanges and IntegerRangesList derivatives. See `?`findOverlaps,GenomicRanges,GenomicRanges-method`` in the GenomicRanges package for methods that operate on GenomicRanges or GRangesList objects.

### Usage

    findOverlaps(query, subject, maxgap=-1L, minoverlap=0L,
                 type=c("any", "start", "end", "within", "equal"),
                 select=c("all", "first", "last", "arbitrary"),
                 ...)

    countOverlaps(query, subject, maxgap=-1L, minoverlap=0L,
                  type=c("any", "start", "end", "within", "equal"),
                  ...)

    overlapsAny(query, subject, maxgap=-1L, minoverlap=0L,
                type=c("any", "start", "end", "within", "equal"),
                ...)
    query %over% subject
    query %within% subject
    query %outside% subject

    subsetByOverlaps(x, ranges, maxgap=-1L, minoverlap=0L,
                     type=c("any", "start", "end", "within", "equal"),
                     invert=FALSE,
                     ...)

    overlapsRanges(query, subject, hits=NULL, ...)

    poverlaps(query, subject, maxgap = 0L, minoverlap = 1L,
              type = c("any", "start", "end", "within", "equal"),
              ...)

    mergeByOverlaps(query, subject, ...)

    findOverlapPairs(query, subject, ...)

### Arguments

`query, subject, x, ranges` | Each of them can be an IntegerRanges (e.g. IRanges, Views) or IntegerRangesList (e.g. IRangesList, ViewsList) derivative. In addition, if `subject` or `ranges` is an IntegerRanges object, `query` or `x` can be an integer vector to be converted to length-one ranges. If `query` (or `x`) is an IntegerRangesList object, then `subject` (or `ranges`) must also be an IntegerRangesList object. If both arguments are list-like objects with names, each list element from the 2nd argument is paired with the list element from the 1st argument with the matching name, if any. Otherwise, list elements are paired by position. The overlap is then computed between the pairs as described below. If `subject` is omitted, `query` is queried against itself. In this case, and only this case, the `drop.self` and `drop.redundant` arguments are allowed. By default, the result will contain hits for each range against itself, and if there is a hit from A to B, there is also a hit for B to A. If `drop.self` is `TRUE`, all self matches are dropped. If `drop.redundant` is `TRUE`, only one of A->B and B->A is returned.
`maxgap` | A single integer >= -1. If `type` is set to `"any"`, `maxgap` is interpreted as the maximum gap that is allowed between 2 ranges for the ranges to be considered as overlapping. The gap between 2 ranges is the number of positions that separate them. The gap between 2 adjacent ranges is 0. By convention when one range has its start or end strictly inside the other (i.e. non-disjoint ranges), the gap is considered to be -1. If `type` is set to anything else, `maxgap` has a special meaning that depends on the particular `type`. See `type` below for more information.
`minoverlap` | A single non-negative integer. Only ranges with a minimum of `minoverlap` overlapping positions are considered to be overlapping. When `type` is `"any"`, at least one of `maxgap` and `minoverlap` must be set to its default value.
`type` | By default, any overlap is accepted. By specifying the `type` parameter, one can select for specific types of overlap. The types correspond to operations in Allen's Interval Algebra (see references). If `type` is `start` or `end`, the intervals are required to have matching starts or ends, respectively. Specifying `equal` as the type returns the intersection of the `start` and `end` matches. If `type` is `within`, the query interval must be wholly contained within the subject interval. Note that all matches must additionally satisfy the `minoverlap` constraint described above. The `maxgap` parameter has special meaning with the special overlap types. For `start`, `end`, and `equal`, it specifies the maximum difference in the starts, ends or both, respectively. For `within`, it is the maximum amount by which the subject may be wider than the query. If `maxgap` is set to -1 (the default), it's replaced internally by 0.
`select` | If `query` is an IntegerRanges derivative: When `select` is `"all"` (the default), the results are returned as a Hits object. Otherwise the returned value is an integer vector parallel to `query` (i.e. same length) containing the first, last, or arbitrary overlapping interval in `subject`, with `NA` indicating intervals that did not overlap any intervals in `subject`. If `query` is an IntegerRangesList derivative: When `select` is `"all"` (the default), the results are returned as a HitsList object. Otherwise the returned value depends on the `drop` argument. When `select != "all" && !drop`, an IntegerList is returned, where each element of the result corresponds to a space in `query`. When `select != "all" && drop`, an integer vector is returned containing indices that are offset to align with the unlisted `query`.
`invert` | If `TRUE`, keep only the ranges in `x` that do not overlap `ranges`.
`hits` | The Hits or HitsList object returned by `findOverlaps`, or `NULL`. If `NULL` then `hits` is computed by calling `findOverlaps(query, subject, ...)` internally (the extra arguments passed to `overlapsRanges` are passed to `findOverlaps`).
`...` | Further arguments to be passed to or from other methods: `drop`: Supported only when `query` is an IntegerRangesList derivative. `FALSE` by default. See `select` argument above for the details. `drop.self`, `drop.redundant`: When `subject` is omitted, the `drop.self` and `drop.redundant` arguments (both `FALSE` by default) are allowed. See `query` and `subject` arguments above for the details.

### Details

A common type of query that arises when working with intervals is finding which intervals in one set overlap those in another.

The simplest approach is to call the `findOverlaps` function on a IntegerRanges or other object with range information (aka "range-based object").

### Value

For `findOverlaps`: see `select` argument above.

For `countOverlaps`: the overlap hit count for each range in `query` using the specified `findOverlaps` parameters. For IntegerRangesList objects, it returns an IntegerList object.

`overlapsAny` finds the ranges in `query` that overlap any of the ranges in `subject`. For IntegerRanges derivatives, it returns a logical vector of length equal to the number of ranges in `query`. For IntegerRangesList derivatives, it returns a LogicalList object where each element of the result corresponds to a space in `query`.

`%over%` and `%within%` are convenience wrappers for the 2 most common use cases. Currently defined as ``%over%` <- function(query, subject) overlapsAny(query, subject)` and ``%within%` <- function(query, subject) overlapsAny(query, subject, type="within")`. `%outside%` is simply the inverse of `%over%`.

`subsetByOverlaps` returns the subset of `x` that has an overlap hit with a range in `ranges` using the specified `findOverlaps` parameters.

When `hits` is a Hits (or HitsList) object, `overlapsRanges(query, subject, hits)` returns a IntegerRanges (or IntegerRangesList) object of the same shape as `hits` holding the regions of intersection between the overlapping ranges in objects `query` and `subject`, which should be the same query and subject used in the call to `findOverlaps` that generated `hits`. Same shape means same length when `hits` is a Hits object, and same length and same elementNROWS when `hits` is a HitsList object.

`poverlaps` compares `query` and `subject` in parallel (like e.g., `pmin`) and returns a logical vector indicating whether each pair of ranges overlaps. Integer vectors are treated as width-one ranges.

`mergeByOverlaps` computes the overlap between query and subject according to the arguments in `...`. It then extracts the corresponding hits from each object and returns a `DataFrame` containing one column for the query and one for the subject, as well as any `mcols` that were present on either object. The query and subject columns are named by quoting and deparsing the corresponding argument.

`findOverlapPairs` is like `mergeByOverlaps`, except it returns a formal `Pairs` object that provides useful downstream conveniences, such as finding the intersection of the overlapping ranges with `pintersect`.

### Author(s)

Michael Lawrence and Hervé Pagès

### References

Allen's Interval Algebra: James F. Allen: Maintaining knowledge about temporal intervals. In: Communications of the ACM. 26/11/1983. ACM Press. S. 832-843, ISSN 0001-0782

### See Also

- Hits and HitsList objects in the S4Vectors package for representing a set of hits between 2 vector-like or list-like objects.

- findOverlaps,GenomicRanges,GenomicRanges-method in the GenomicRanges package for methods that operate on GRanges or GRangesList objects.

- The NCList class and constructor.

- The IntegerRanges, Views, IntegerRangesList, and ViewsList classes.

- The IntegerList and LogicalList classes.

### Examples

    ## ---------------------------------------------------------------------
    ## findOverlaps()
    ## ---------------------------------------------------------------------

    query <- IRanges(c(1, 4, 9), c(5, 7, 10))
    subject <- IRanges(c(2, 2, 10), c(2, 3, 12))

    findOverlaps(query, subject)

    ## at most one hit per query
    findOverlaps(query, subject, select="first")
    findOverlaps(query, subject, select="last")
    findOverlaps(query, subject, select="arbitrary")

    ## including adjacent ranges in the result
    findOverlaps(query, subject, maxgap=0L)

    query <- IRanges(c(1, 4, 9), c(5, 7, 10))
    subject <- IRanges(c(2, 2), c(5, 4))

    ## one IRanges object with itself
    findOverlaps(query)

    ## single points as query
    subject <- IRanges(c(1, 6, 13), c(4, 9, 14))
    findOverlaps(c(3L, 7L, 10L), subject, select="first")

    ## special overlap types
    query <- IRanges(c(1, 5, 3, 4), width=c(2, 2, 4, 6))
    subject <- IRanges(c(1, 3, 5, 6), width=c(4, 4, 5, 4))

    findOverlaps(query, subject, type="start")
    findOverlaps(query, subject, type="start", maxgap=1L)
    findOverlaps(query, subject, type="end", select="first")
    ov <- findOverlaps(query, subject, type="within", maxgap=1L)
    ov

    ## Using pairs to find intersection of overlapping ranges
    hits <- findOverlaps(query, subject)
    p <- Pairs(query, subject, hits=hits)
    pintersect(p)

    ## Shortcut
    p <- findOverlapPairs(query, subject)
    pintersect(p)

    ## ---------------------------------------------------------------------
    ## overlapsAny()
    ## ---------------------------------------------------------------------

    overlapsAny(query, subject, type="start")
    overlapsAny(query, subject, type="end")
    query %over% subject    # same as overlapsAny(query, subject)
    query %within% subject  # same as overlapsAny(query, subject,
                              #                     type="within")

    ## ---------------------------------------------------------------------
    ## overlapsRanges()
    ## ---------------------------------------------------------------------

    ## Extract the regions of intersection between the overlapping ranges:
    overlapsRanges(query, subject, ov)

    ## ---------------------------------------------------------------------
    ## Using IntegerRangesList objects
    ## ---------------------------------------------------------------------

    query <- IRanges(c(1, 4, 9), c(5, 7, 10))
    qpartition <- factor(c("a","a","b"))
    qlist <- split(query, qpartition)

    subject <- IRanges(c(2, 2, 10), c(2, 3, 12))
    spartition <- factor(c("a","a","b"))
    slist <- split(subject, spartition)

    ## at most one hit per query
    findOverlaps(qlist, slist, select="first")
    findOverlaps(qlist, slist, select="last")
    findOverlaps(qlist, slist, select="arbitrary")

    query <- IRanges(c(1, 5, 3, 4), width=c(2, 2, 4, 6))
    qpartition <- factor(c("a","a","b","b"))
    qlist <- split(query, qpartition)

    subject <- IRanges(c(1, 3, 5, 6), width=c(4, 4, 5, 4))
    spartition <- factor(c("a","a","b","b"))
    slist <- split(subject, spartition)

    overlapsAny(qlist, slist, type="start")
    overlapsAny(qlist, slist, type="end")
    qlist

    subsetByOverlaps(qlist, slist)
    countOverlaps(qlist, slist)

[Package IRanges version 2.14.12 Index]