# Vectorize: Vectorize a Scalar Function

Description Usage Arguments Details Value Examples

## Description

`Vectorize` creates a function wrapper that vectorizes the action of its argument `FUN`.

## Usage

 ```1 2``` ```Vectorize(FUN, vectorize.args = arg.names, SIMPLIFY = TRUE, USE.NAMES = TRUE) ```

## Arguments

 `FUN` function to apply, found via `match.fun`. `vectorize.args` a character vector of arguments which should be vectorized. Defaults to all arguments of `FUN`. `SIMPLIFY` logical or character string; attempt to reduce the result to a vector, matrix or higher dimensional array; see the `simplify` argument of `sapply`. `USE.NAMES` logical; use names if the first ... argument has names, or if it is a character vector, use that character vector as the names.

## Details

The arguments named in the `vectorize.args` argument to `Vectorize` are the arguments passed in the `...` list to `mapply`. Only those that are actually passed will be vectorized; default values will not. See the examples.

`Vectorize` cannot be used with primitive functions as they do not have a value for `formals`.

It also cannot be used with functions that have arguments named `FUN`, `vectorize.args`, `SIMPLIFY` or `USE.NAMES`, as they will interfere with the `Vectorize` arguments. See the `combn` example below for a workaround.

## Value

A function with the same arguments as `FUN`, wrapping a call to `mapply`.

## 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 25 26 27 28 29 30 31 32 33``` ```# We use rep.int as rep is primitive vrep <- Vectorize(rep.int) vrep(1:4, 4:1) vrep(times = 1:4, x = 4:1) vrep <- Vectorize(rep.int, "times") vrep(times = 1:4, x = 42) f <- function(x = 1:3, y) c(x, y) vf <- Vectorize(f, SIMPLIFY = FALSE) f(1:3, 1:3) vf(1:3, 1:3) vf(y = 1:3) # Only vectorizes y, not x # Nonlinear regression contour plot, based on nls() example require(graphics) SS <- function(Vm, K, resp, conc) { pred <- (Vm * conc)/(K + conc) sum((resp - pred)^2 / pred) } vSS <- Vectorize(SS, c("Vm", "K")) Treated <- subset(Puromycin, state == "treated") Vm <- seq(140, 310, length.out = 50) K <- seq(0, 0.15, length.out = 40) SSvals <- outer(Vm, K, vSS, Treated\$rate, Treated\$conc) contour(Vm, K, SSvals, levels = (1:10)^2, xlab = "Vm", ylab = "K") # combn() has an argument named FUN combnV <- Vectorize(function(x, m, FUNV = NULL) combn(x, m, FUN = FUNV), vectorize.args = c("x", "m")) combnV(4, 1:4) combnV(4, 1:4, sum) ```