Calculations using Inline Functions

Hello... I'm still a beginner when it comes to using MATLAB and I can't seem to figure this equation out.

My Code:

t = (-100:0.01:100);

g = inline ('(exp(-t).*(cos(2*pi*t))).*(t>=0)','t');
h = inline ('g((2*t)+1) + g(1-t)','t','g');

E = inline('((g(2*t+1) + g(1-t)).^2)','t','g'); % square of the function h(t)

En = quad(E(h,t),-100,100);
En (E,t)

Error:

Error using inlineeval (line 14)
Error in inline expression ==> ((g(2*t+1) + g(1-t)).^2)
 Undefined function 'mtimes' for input arguments of type
 'inline'.

Error in inline/subsref (line 23)
    INLINE_OUT_ = inlineeval(INLINE_INPUTS_,
    INLINE_OBJ_.inputExpr, INLINE_OBJ_.expr);

Error in BA2 (line 27)
En = quad(E(h,t),-100,100);

Please and thank you.

Answer 1

[Adam]

I've never used 'inline' and didn't even know it existed, but the documentation says:

'inline will be removed in a future release. Use Anonymous Functions instead.'

so I would suggest not using inline if you intend to keep your code for future usage too. I use anonymous functions a lot which is probably why I never knew about the 'inline' function.

It looks like you have too many closing parenthesis in your definition of 'g' though.

Try using the following instead as an anonymous function:

g = @(t) exp(-t) .* cos( 2 * pi * t ) .* ( t >= 0 );
h = @(t) g(( 2 * t ) + 1 ) + g( 1 - t )
E = @(t) h(t).^2

I think that should work for E...no need to define it in terms of g if it is just h squared.

Then I assume this should give the right answer:

En = quad( E, -100, 100 );

Again though the 'quad' function says it will be removed in a future release, but maybe if you are using an old Matlab you don't have the suggested replacement function.

[Annalise]

That reduced the number of errors I've got, however, a new error shows up for E.

E = @(t) h(t).^2;

En = quad(E(h,t),-100,100);
En (h,t)

The error comes up as:

Error using @(t)h(t).^2
Too many input arguments.

Error in BA2 (line 27)
En = integral(E(h,t),-100,100);

Both with quad and integral, I keep getting the same error over and over.

[Annalise]

Oh.. I got it. Thank you very very much!!

[Adam]

I'm not too familar with quad or integral in terms of how you feed in the single argument to the 'E' function, but:

En = quad( E, -100, 100 );

certainly gave a result for me without error. Whether it was a correct result or not I'm not sure.

Usually you would just call E as:

    res = E(t);

but when it is being passed as a function handle to 'quad' or 'integral' that function appears to expect format more like the above.