R: Generic extended version of R match.fun

match.funfn {gsubfn} | R Documentation

## Generic extended version of R match.fun

### Description

A generic `match.fun`.

### Usage

    match.funfn(FUN, descend = TRUE)

### Arguments

`FUN` | Function, character name of function or formula describing function.
`descend` | logical; control whether to search past non-function objects.

### Details

The default method is the same as `match.fun` and the `formula` method is the same as `as.function.formula`. This function can be used within the body of a function to convert a function specification whether its a function, character string or formula into an actual function.

### Value

Returns a function.

### See Also

See Also `match.fun`, `as.function.formula`.

### Examples

    # return first argument evaluated at second argument squared.
    sq <- function(f, x) {
       f <- match.funfn(f)
       f(x^2)
    }

    # call sq using different forms for function
    sq(function(x) exp(x)/x, pi)
    f <- function(x) exp(x)/x
    sq("f", pi)
    sq(~ exp(x)/x, pi)
    sq(x ~ exp(x)/x, pi)

[Package gsubfn version 0.6-6 Index]