struct to non struct error in integral calc

Hello , i am getting this error

"Struct contents reference from a non-struct array object."

its a simmpe formulas, why i am getting error?

Thanks

a = @(th)(((sin((x./2).*cos(th))./cos(th)).^2).*(besselj(0,(k.L.*sin(th)))).*(sin(th)).^3);

a1 = integral(a,0,pi);

[Andrei Bobrov]

What is it k.L ?

[fima v]

parameters of dimentions and wavelength

Answer 1

[Walter Roberson]

I suspect

k.L.*sin(th)

should be

k.*L.*sin(th)

[fima v]

wowwww thank you very much :-)