Passing a function as an argument when the function itself has been passed

What I need to do is the following. I have some functions f, g, and h. Now I want to pass function f to g. To do this, I write

g(@f)

So my function g gets as an argument my function f. Inside function g, I call function h, and I want to pass f as an argument. So, my function g looks kind of like

function [y] = g(x)

h(@x)

end

and my function h looks like

function [y] = h(x)

x(0.5)

end

However, I am not allowed to write h(@x) inside the function g, as I get the error message ""x" was previously used as a variable, conflicting with its use here as the name of a function or command."

On the other hand, if I write h(x) inside the function g, then I get the error message "Array indices must be positive integers or logical values." since the x in the function h is not interpreted as a function anymore. So how can I make this work, how can I pass a function twice?

Answer 1

[madhan ravi]

Using anonymous function:

f = @(x) exp(x);
g = @(x) sin(f(x)); 
h = @(x) 2*g(x); 

h(1) % Evaluation

% or by Nested function https://in.mathworks.com/help/matlab/matlab_prog/nested-functions.html?searchHighlight=Nested%20function&s_tid=doc_srchtitle

Answer 2

[Sulaymon Eshkabilov]

If I have undertood your problem correctly, what you are trying to do is g(h(f(x))), right?!

In other words, to pass f(x) into h function as its argument and h into g function as its argument.

f = @(x) exp(x);   % E.g. f = exp(x); or can be any function or math expression with a variable x or x, y, z
g = @(f)(sin(f));  % E.g. g = sin(exp(x)) 
h = @(g)(2*g);     % E.g. h = 2*sin(exp(x))

[madhan ravi]

What?

Verify the results

For instance

2*sin(exp(1)) %and h(1) % your way see if both the results are same. Hint: No.

Answer 3

[Sulaymon Eshkabilov]

You are using a wrong command what I have proposed. The correct way of calling the anounymous function in my proposed solution is: h(g(f(1)))

Answer 4

[Sulaymon Eshkabilov]

Now you can verify this with any function.