lcSuffix: Compute the longest common prefix or suffix of a string

Description Usage Arguments Details Value Author(s) See Also Examples

View source: R/strings.R

Description

These functions find the longest common prefix or suffix among the strings in a character vector.

Usage

1
2
3
lcPrefix(x, ignore.case=FALSE)
lcPrefixC(x, ignore.case=FALSE)
lcSuffix(x, ignore.case=FALSE)

Arguments

x

a character vector.

ignore.case

A logical value indicating whether or not to ignore the case in making comparisons.

Details

Computing the longest common suffix is helpful for truncating names of objects, like microarrays, that often have a common suffix, such as .CEL.

There are some potential problems with the approach used if multibyte character encodings are being used.

lcPrefixC is a faster implementation in C. It only handles ascii characters.

Value

The common prefix or suffix.

Author(s)

R. Gentleman

See Also

nchar, nchar

Examples

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
s1 <- c("ABC.CEL", "DEF.CEL")
lcSuffix(s1)

s2 <- c("ABC.123", "ABC.456")
lcPrefix(s2)


CHK <- stopifnot

CHK(".CEL" == lcSuffix(s1))
CHK("bc" == lcSuffix(c("abc", "333abc", "bc")))
CHK("c" == lcSuffix(c("c", "abc", "xxxc")))
CHK("" == lcSuffix(c("c", "abc", "xxx")))

CHK("ABC." == lcPrefix(s2))
CHK("ab" == lcPrefix(c("abcd", "abcd123", "ab", "abc", "abc333333")))
CHK("a" == lcPrefix(c("abcd", "abcd123", "ax")))
CHK("a" == lcPrefix(c("a", "abcd123", "ax")))
CHK("" == lcPrefix(c("a", "abc", "xxx")))

CHK("ab" == lcPrefixC(c("abcd", "abcd123", "ab", "abc", "abc333333")))
CHK("a" == lcPrefixC(c("abcd", "abcd123", "ax")))
CHK("a" == lcPrefixC(c("a", "abcd123", "ax")))
CHK("" == lcPrefixC(c("a", "abc", "xxx")))

Bioconductor/Biobase documentation built on June 16, 2018, 10:46 p.m.