Problem to extract real and imaginary parts?

syms E0 real positive
syms x real
syms y real
syms z real
syms x0 real
syms y0 real
syms z0 real
syms R real positive
syms e0 real positive
syms ew real positive
syms er real
syms ei real positive
syms kn real positive

rk=[x;y;z]; %vector
r0=[x0;y0;(z0+R)]; %vector

Eplx=0;Eply=0;Eplz=E0;
em=er+ei*1i;
a0=4*pi*R^3*((em-ew)/(em+2*ew));

px=ew*e0*a0*Eplx;
py=ew*e0*a0*Eply;
pz=ew*e0*a0*Eplz;
p=[px;py;pz];

E1=kn^2.*cross((rk-r0),cross(p,(rk-r0))).*exp(1i*kn*norm(rk-r0))./((norm(rk-r0)).^3);

E2=((1-1i*kn*norm(rk-r0))./(norm(rk-r0).^2)).*(3*(rk-r0).*dot((rk-r0),p)-(n.^2.*p)).*exp(1i*kn*norm(rk-r0))./((norm(rk-r0)).^3);

It is not possible to extract real and imag parts from E1 and E2. Where can be the problem? How can it be solved? Is it too complex for Matlab to recognize Re and Im parts in such expression?

Thank you!

[Walter Roberson]

n is undefined in the final line.

[Ivan]

the problem remains still.. even if I substitute n=norm(rk-r0)

Answer 1

[Walter Roberson]

rewrite( expand(E1), 'sincos' )

and you might want to simplify() afterwards.