getting multiple curves instead one single curve

I am getting multiple curves instead of getting one curve by using the following code. here ep_1 and ep_2 data I am importing from outside which contains 69 data points.

ep_d=1.3641;
ep= ep_1 +1i*ep_2;
theta =-90:2:90;
lambda = 1240./1.5;
y =  lambda./(sqrt((ep_d.*ep)./(ep_d+ep))- sin(theta*(pi/180)));
plot (theta ,real(y) )

I have attached my output but here I am supposed to get only one curve. Kindly help me in this problem. How can I get one curve only?

Answer 1

[VBBV]

ep_d=1.3641;ep_1 = 1; ep_2 = 2;
ep= ep_1 +1i*ep_2;
theta =-90:2:90;
lambda = 1240./1.5;
y =  lambda./(sqrt((ep_d.*ep)./(ep_d+ep))- sin(theta*(pi/180)));
plot (theta ,real(y) )

[Vaswati Biswas]

Thank you so much