how can I plot diffracted filed in polar coordinate?

hi, I want to plot the diffracted field by a PEC wedge. I posted the equation and the main plot and my code's figure in an Image. and this is my matlab code,but I receive this error:

 Warning: Imaginary parts of complex X and/or Y arguments ignored 
 > In polar (line 192)
 In wedgemodal11balanis (line 28) 

 my code:
clc 
clear all

a=pi/4

q=(pi/4:0.01:7*(pi/4))

c=5*pi/12

d=1

f=3*(10^10)

y=(3*(10^8))/f

p=y

w=2*pi*f

miu=1

b=(2*pi)/y

o=q-a

u=c-a

e0=(sqrt((pi*1j/(2*b))))*((w*miu)/(pi-a))*((exp(-1j*b*d))/sqrt(d))

inf=10

for m=1:inf

e1=1j^(m/2)

e2=besselj(m/2,b*p)

e3=sin((m/2)*c)

e4=sin((m/2)*q)

et=(10*log10(e0*e1*e2*e3*e4))

polar(o,et)

end

Answer 1

[Bjorn Gustavsson]

Perhaps you want to plot the amplitude of the field? If so just change

et=(10*log10(e0*e1*e2*e3*e4))

to ab_et=(10*log10(abs(e0*e1*e2*e3*e4)));

HTH

[mohammad rashedi]

thanks,yes,I want to plot the amplitude. I changed it,but nothing happened.new figure and old figure are same. I think I have a problem in plotting figure. I don't know where is the problem.