feval - Evaluate function - MATLAB (original) (raw)

Syntax

Description

[[y1,...,yN](#f71-813114-y1yN)] = feval([fun](#f71-813114-fun),[x1,...,xM](#f71-813114-x1xM)) evaluates a function using its name or its handle, and using the input arguments x1,...,xM.

The feval function follows the same scoping and precedence rules as calling a function handle directly. For more information, see Create Function Handle.

example

Examples

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Evaluate Function with Function Name as Character Vector

Round the value of pi to the nearest integer using the name of the function.

fun = 'round'; x1 = pi; y = feval(fun,x1)

Round the value of pi to two digits to the right of the decimal point.

x2 = 2; y = feval(fun,x1,x2)

Input Arguments

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fun — Function to evaluate

function name | function handle

Function to evaluate, specified as a function name or a handle to a function. The function accepts M input arguments, and returns N output arguments. To specify fun as a function name, do not include path information.

Invoking feval with a function handle is equivalent to invoking the function handle directly.

Example: fun = 'cos'

Example: fun = @sin

x1,...,xM — Inputs to evaluated function

depends on function

Inputs to the evaluated function. The types of the inputs depend on the function, fun.

Output Arguments

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y1,...,yN — Outputs from evaluated function

depends on function

Outputs from evaluated function. The types of the outputs depend on the function, fun.

Tips

• If you have a function handle, it is not necessary to use feval because you can invoke the function handle directly. The results of the following statements are equivalent.
  fh = @eig;
  [V,D] = fh(A)
  [V,D] = feval(@eig,A)
• To evaluate a nested or local function using feval, use a function handle instead of the function name. For more information, see Call Local Functions Using Function Handles.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• The code generator automatically interprets feval as an extrinsic function. For more information, see Use MATLAB Engine to Execute a Function Call in Generated Code (MATLAB Coder).
• The code generator does not support the use offeval to call local functions.
• The code generator does not support the use offeval to call functions that are located in a private folder.

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

Version History

Introduced before R2006a