Function handles in MATLAB

Introduction

Function handles let you store and use functions like variables. This helps you call functions later or pass them around easily.

When you want to pass a function as input to another function.

When you want to call a function multiple times without rewriting its name.

When you want to create flexible code that can use different functions.

When you want to store a function in a variable for later use.

When you want to use anonymous functions for quick calculations.

Syntax

MATLAB

f = @functionName;

% or for anonymous functions:
f = @(input) expression;

Use the @ symbol before the function name to create a function handle.

Anonymous functions let you write small functions without creating a separate file.

Examples

Create a handle to the built-in sine function and call it with pi/2.

MATLAB

f = @sin;
result = f(pi/2);

Create an anonymous function to square a number and use it.

MATLAB

square = @(x) x.^2;
result = square(4);

Create a handle to the max function and find the maximum in an array.

MATLAB

f = @max;
result = f([1, 5, 3]);

Sample Program

This program creates a function handle 'square' to calculate squares. Then it uses arrayfun to apply it to each number in the array and displays the results.

MATLAB

square = @(x) x.^2;
nums = [1, 2, 3, 4];
squares = arrayfun(square, nums);
disp(squares);

Important Notes

Function handles can be passed as arguments to other functions like arrayfun or ode45.

Anonymous functions are useful for quick, simple operations without making a separate file.

Remember to use dot operators (like .^) inside anonymous functions to work element-wise on arrays.

Summary

Function handles let you treat functions like variables.

Use @ to create a handle to named or anonymous functions.

They help make your code flexible and reusable.