plot the recieved power as a function of distance

I need to plot recieved power as a function of distance but i cant get the correct answer. may any one help me?

the function is pr and we need to plot (ds,pr).

i calculate all of parameters i just cant plot it as it desired.

here is the code that i write.

note: delta phi=2*pi*(d(a)-ds))/(lambda)

r=[-1.3772 - 0.3563i -0.7217 + 0.1599i -0.6364 + 0.1913i -1.4569 - 0.4529i]

d=[204.2084 202.5438 200.1599 204.2084]

for a=1:4

ds=200;

gmain=20; %in db

pt=30; % in dbm

lambda=0.005;

g=[21 22 23 25]; %this g matrix is just an assumption and not real values--i should find and replace them with valid values

q=(20*log10(r(a))+g(a)+20*log10(exp((-2i*pi*(d(a)-ds))/(lambda))))-(20*log10(d(a)))

end

ds=0:5:200

pr=pt+20*log10(1/(800*pi))+((gmain-(20*log10(ds))+(q)))

plot(ds,pr)