Function with double arguments

Can I make this?

function[g]= forward(f(x),x)

    for j=5:5:40;
       h=inv(j)
       g=(f(x)+4*f(h)-f(h+h))/(h+h)  
    end
    end

[Walter Roberson]

Do you mean something different for inv(j) than 1/j ?

Answer 1

[the cyclist]

You want to call a MATLAB function an argument that is itself a function, right? You can do that as follows. Define your function like this:

function [g] = forward(f,x)

      for j=5:5:40;
         h = inv(j);
         g = (f(x)+4*f(h)-f(h+h))/(h+h);
      end

end

and call it using a "function handle" like this:

forward(@sin,7) % Argument is the MATLAB built-in sine function

or like this

my_func = @(x) x^2; % Define your own function, and assign its handle
forward(my_func,7) % Argument is function defined by you

[Claudia Santos]

Oh thank you! Can you explain to me please this line of code?

my_func = @(x) x^2;

[the cyclist]

It is an anonymous function.

So, if you now do

my_func(5)

you will get 25 as output.

The best form of thanks is to upvote and/or accept solutions that helped you. This rewards the contributor, and can point future users to helpful answers.