error when trying to integrate this function in a plot

so im trying to integrate this, but i mostly get errors when trying a few things:

a = logspace(-3,0,200)

fun = @(x)((exp(-H1(1)*abs(a)-H2*sqrt(a.^2+m0^2)))./(abs(a)+sqrt(a.^2+m0^2)).*(exp(j*a.*(X1(1)-Xg(1)))))

Zint = fun(x)

Zint_real = real(Zint);

Zint_imag = imag(Zint);

semilogx(a,Zint_real)

hold on

semilogx(a,Zint_imag)

hold off

integrate(fun(x))

also get this error message: Undefined function 'integrate' for input arguments of type 'double'.

what am i doing wrong?

[Torsten]

There is no internal function named "integrate" in MATLAB.

[Danny]

so how can i integrate this function? it's not clear to me

[Torsten]

Your function "fun" does not depend on x. This makes integration very simple.

[Danny]

it does depend on a, so i should atleast change x to a right?

[Torsten]

Take a look at

https://de.mathworks.com/help/symbolic/int.html

for symbolic integration and

https://de.mathworks.com/help/matlab/ref/integral.html

for numerical integration.