#### 11.11.3 Inline Functions

An inline function is created from a string containing the function body using the `inline` function. The following code defines the function f(x) = x^2 + 2.

    f = inline ("x^2 + 2");

After this it is possible to evaluate f at any x by writing `f(x)`.

Built-in Function: inline (str)
Built-in Function: inline (str, arg1, …)
Built-in Function: inline (str, n)

  Create an inline function from the character string str.

  If called with a single argument, the arguments of the generated function are extracted from the function itself. The generated function arguments will then be in alphabetical order. It should be noted that i, and j are ignored as arguments due to the ambiguity between their use as a variable or their use as an inbuilt constant. All arguments followed by a parenthesis are considered to be functions. If no arguments are found, a function taking a single argument named `x` will be created.

  If the second and subsequent arguments are character strings, they are the names of the arguments of the function.

  If the second argument is an integer n, the arguments are `"x"`, `"P1"`, …, `"PN"`.

  Programming Note: The use of `inline` is discouraged and it may be removed from a future version of Octave. The preferred way to create functions from strings is through the use of anonymous functions (see Anonymous Functions) or `str2func`.

  See also: argnames, formula, vectorize, str2func.

Built-in Function: argnames (fun)

  Return a cell array of character strings containing the names of the arguments of the inline function fun.

  See also: inline, formula, vectorize.

Built-in Function: formula (fun)

  Return a character string representing the inline function fun. Note that `char (fun)` is equivalent to `formula (fun)`.

  See also: argnames, inline, vectorize.

Function File: symvar (s)

  Identify the argument names in the function defined by a string. Common constant names such as `pi`, `NaN`, `Inf`, `eps`, `i` or `j` are ignored. The arguments that are found are returned in a cell array of strings. If no variables are found then the returned cell array is empty.