MATLAB Programming

Function Handles
Function Handles
A function handle is a MATLAB value that provides a means of calling a
function indirectly. You can pass function handles in calls to other functions
(often called function functions). You can also store function handles in data
structures for later use (for example, as Handle Graphics callbacks).
This section covers the following topics:
• “Constructing a Function Handle” on page 4-23
• “Calling a Function Using Its Handle” on page 4-24
• “Functions That Operate on Function Handles” on page 4-26
• “Comparing Function Handles” on page 4-26
• “Additional Information on Function Handles” on page 4-31
Constructing a Function Handle
Use the following syntax to construct a function handle, preceding the name
of the function with an @ sign. Use only the function name, withnopath
information, after the @ sign:
fhandle = @functionname
MATLABmapsthehandletothefunction you specify and saves this mapping
information in the handle. If there is more than one function with this name,
MATLAB maps to the one function source it would dispatch to if you were
actually calling the function.
A function handle retains that same mapping even if its corresponding
function goes out of scope. For example, if, after creating the handle, you
changetheMATLABpathsothatadifferentfunctionofthesamenamenow
takes precedence, invoking the function handle still executes the code to
which the handle was originally mapped.
Handles to Anonymous Functions
Another way to construct a function handle is to create an anonymous
function. For example,
4-23