how to draw a 5×5 three-dimensional planar array with isotropic elements using the formula AF_(n ) (θ,ϕ)= {1/M sin⁡(M/2 ψ_x )/sin⁡(ψ_x/2) }{1/N sin⁡(N/2 ψ_y )/sin⁡(ψ_y/2) }