Ecfun (version 0.1-4)

whichAeqB: Index of a single match

Description

Return which(A %in% B) if it has length 1; give an error message otherwise.

Usage

whichAeqB(A, B, errNoMatch='no match',
                      err2Match='more than one match')

Arguments

A

A vector which may have a single match in B.

B

A vector of possible matches for A.

errNoMatch

a character string: error message if no match found.

err2Match

a character string: error message if multiple matches found.

Value

• a single integer giving the index of the match in A.

See Also

interpPairs

Examples

a2b <- whichAeqB(letters, 'b')

stopifnot(
all.equal(a2b, 2)
)