The document explains the concept of function handles in MATLAB, which are data types that store associations with functions, allowing indirect calls to both built-in and user-defined functions. It discusses various uses, such as passing functions to other functions, callback functions in GUI programming, and creating anonymous functions. Additionally, it covers local and private functions, emphasizing their visibility and scope within the code structure.

1. Function Function
Local Function
Private Function
MOREON
USERDEFINEDFUNCTION
Shameer A Koya
http://electricalenggtutorial.blogspot.com

2. A function handle is a data type that stores an
association to a function.
the functions can be built-in, user defined, or
anonymous
It is used to call a function indirectly.
To make a function handle for built-in or user-
defined function, put the @ symbol in front of
function name
fhandle = @functionname
function handle for MATLAB ones function is @ones
FUNCTION HANDLE

3. Typical uses are:
Pass a function to another function
(called function functions).
Specify callback functions. (GUI
programming)
Construct handles to inline functions or
anonymous functions.
Call local functions from outside the main
function
USES OF FUNCTION HANDLE

4.  Anonymous function
sqr = @(x) x.^2
 Calling function indirect:
function y = Sqr(x)
y = x.^2;
end
f = @Sqr;
a = 2;
b = f(a);
b =
4
 Pass to another function
z = integral(f,0,1);
EXAMPLES

5. A MATLAB function that accepts another
function as an input is called a function
function
Function handles are used for passing
functions to function functions
Syntax for function function is same as simple
functions, but one or more input arguments
will be function handles.
FUNCTION FUNCTIONS

6.  From the previous example:
z = quad(f,0,1);
z =
0.33333
 Calculate the integral for the interval specified.
fzero(@sqr,-3,3)
 Finds the zeros of the function with in the range
 Can be used to plot the functions
x = linspace(-3,3,100);
figure;
plot(x,f(x))
EXAMPLES

7.  Multiple functions within one function file
 Name of function file should be name of main
function.
 Main function can be called from the command
window or any other function.
 Local functions are typed in any order after the
main function.
 Local functions are only visible to other functions in
the same file. (They are not visible to the functions
out side or command window).
LOCAL FUNCTION (SUB-FUNCTION)

8. function [a, b, c] = basicmath(x, y)
% basicmath is the main function.
a = add(x,y);
b = sub(x,y);
c = mult(x,y);
end
function l = add(u,v)
% add is a local function.
l = u+v;
end
function m = sub(u,v)
% sub is another local function.
m = u-v;
end
function n = mult(u,v)
% sub is another local function.
n = u*v;
end
EXAMPLE

9.  A private function is a function residing in a
subdirectory with the name private.
 Private functions are visible only to functions in the
parent directory.
 They are useful when we want to limit the scope of
a function.
 You cannot call the private function from the
command line or from functions outside the parent
of the private folder.
PRIVATE FUNCTIONS