ABSTRACT
A function handle (@) is a reference to a function that can be treated as a variable. It can be copied, placed in cell array, and evaluated just like a regular function. For example,
f = @sqrt
f(2)
sqrt(2)
“8primer” — #84
The str2func function converts a string to a function handle. For example,
f = str2func(’sqrt’)
f(2)
Function handles can refer to built-in MATLAB functions, to your own function in an M-file, or to anonymous functions. An anonymous function is defined with a one-line expression, rather than by an M-file. Try:
g = @(x) x^2-5*x+6-sin(9*x)
g(1)
Some MATLAB functions that operate on function handles need to evaluate the function on a vector, so it is often better to define an anonymous function (or M-file) so that it can operate entry-wise on scalars, vectors, or matrices. Try this instead:
g = @(x) x.^2-5*x+6-sin(9*x)
g([0 1])
The general syntax for an anonymous function is
handle = @(arg1, arg2, ...) expression
Here is an example with two input arguments, which computes the 2-norm of a vector of length 2.
