My function of L-norm doesn't work

I wrote a function file that calculates L^2 norm of the difference between 2 functions at the certain area:

function l = Lnorm(f1,f2)
    l = sqrt(integral(@(x) (f1 - f2).^2, -8/5, 8/7));
end

Then i tested it with the code below:

f1 = x.^2;
f2 = x.^4;
Lnorm(f1, f2)

It sent me an error message: Error using integralCalc/finalInputChecks

Output of the function must be the same size as the input. If FUN is an array-valued integrand,

set the 'ArrayValued' option to true"

How to fix this?

Answer 1

[Dyuman Joshi]

f1 and f2 need to be defined as function handles.Notice the updated syntax used in the integrand to integral() as well -

f1 = @(x) x.^2;
f2 = @(x) x.^4;
Lnorm(f1, f2)

ans = 1.4474

function l = Lnorm(f1,f2)
    l = sqrt(integral(@(x) (f1(x) - f2(x)).^2, -8/5, 8/7));
end

[Dyuman Joshi]

Any updates, @Do?