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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)`

.

**Caution**: MATLAB has begun the process of deprecating inline
functions. At some point in the future support will be dropped and eventually
Octave will follow MATLAB and also remove inline functions. Use anonymous
functions in all new code.

- 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 built-in 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"`

, …,`"P`

.`N`"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`

.

- Built-in Function:
**argnames***(*`fun`) Return a cell array of character strings containing the names of the arguments of the inline function

`fun`.

- Built-in Function:
**formula***(*`fun`) Return a character string representing the inline function

`fun`.Note that

`char (`

is equivalent to`fun`)`formula (`

.`fun`)

- Function File:
`vars`=**symvar***(*`str`) Identify the symbolic variable names in the string

`str`.Common constant names such as

`i`

,`j`

,`pi`

,`Inf`

and Octave functions such as`sin`

or`plot`

are ignored.Any names identified are returned in a cell array of strings. The array is empty if no variables were found.

Example:

symvar ("x^2 + y^2 == 4") ⇒ { [1,1] = x [2,1] = y }