How can I retrieve an element from this array of functions, as a matlabFunction?

y = @(t,y) [10*(y(2)-y(1)), y(1)*(28-y(1))-y(2), y(1)*y(2)-8*y(2)/3, (y(1)+y(2))^2, (y(1)+y(2)^4)/(5+y(1)*y(2))];

I want to have that

z = y(1) = 10*(y(2)-y(1))

but y(1) already throws an error

Answer 1

[Stephen23]

Use a cell array to store function handles:

 C{1} = @(t,y) 10*(y(2)-y(1));
 C{2} = @(t,y) y(1)*(28-y(1))-y(2);
 C{3} = @(t,y) y(1)*y(2)-8*y(2)/3;
 C{4} = @(t,y) (y(1)+y(2))^2;
 C{5} = @(t,y) (y(1)+y(2)^4)/(5+y(1)*y(2));

And use it like this:

 z = C{1};
 z(tval,yval)

or even simply:

C{1}(tval,yval)

I note that none of your functions use the first input t : is this intentional?

[Avetik Sarikyan]

Thank you very much it worked for me. Also is there a way to calculate gradient of let's say C{1}?

[Stephen23]

"Also is there a way to calculate gradient of let's say C{1}?"

Numerically: define vectors of points and call the function for each point: currently you will need to use a loop (if you wrote vectorized code a loop would not be required). After that, call numeric gradient on those points.

Symbolically: you would need to define the functions using symbolic variables, and then use symbolic gradient.