char.expand               package:base               R Documentation

Expand a String with Respect to a Target Table

Description:

     Seeks a unique match of its first argument among the elements of
     its second.  If successful, it returns this element; otherwise, it
     performs an action specified by the third argument.

Usage:

     char.expand(input, target, nomatch = stop("no match"))

Arguments:

   input: a character string to be expanded.

  target: a character vector with the values to be matched against.

 nomatch: an R expression to be evaluated in case expansion was not
          possible.

Details:

     This function is particularly useful when abbreviations are
     allowed in function arguments, and need to be uniquely expanded
     with respect to a target table of possible values.

Value:

     A length-one character vector, one of the elements of 'target'
     (unless 'nomatch' is changed to be a non-error, when it can be a
     zero-length character string).

See Also:

     'charmatch' and 'pmatch' for performing partial string matching.

Examples:

     locPars <- c("mean", "median", "mode")
     char.expand("me", locPars, warning("Could not expand!"))
     char.expand("mo", locPars)

