Plot E-field pattern

Greetings,

I can use some help in plottng an E-field pattern for an array of nfinitesimal dipole elements placed along the z-axis. It is

E(θ) = sin(θ) (z-1)(z^3 - 1)

d = lambda/2

Where z=e^(jkdcosθ ), the far-field pattern of an infinitesimal dipole antenna is approximated with sin(θ), and β = 0.

I need to plot |E(θ)|^2 for θ є [0degrees,180degrees] in linear and dB scale

I have no problems doing the analytical calculations, but I admit my coding skills need practice. If anyone can write up the code or at lleast write up a template. I am a grad student trying to beef up my Matlab skills. Thank you!