Problems with the Y axis of my 2D graph

Hello! Could someone please help me, I want my graph 1 to look like graph 2 but I don't know how to fix the Y axis. :(

it's for the blue line.

1)

2)

My code:

%Permitividad Parte Real

e_inf = 11.7 ;

Wp = 1.0856e11;

gamma = 2.3518e9 ;

w1 = 1e13;

w2 = 1e13;

w3 = 1e15;

index = 0;

K = w1:w2:w3;

for w = 1:length(K)

index = index + 1 ;

e(index) = e_inf - (Wp^2/K(w)^2+1i*K(w)*gamma);

f(index) = K(w);

x(index) = f(index) ;

y(index) = real(e(index));

end

semilogx(x,y)

Answer 1

[Sulaymon Eshkabilov]

Take smaller step size for w, eg.:

e_inf = 11.7 ;           
Wp   = 1.0856e11;               
gamma = 2.3518e9 ;
w1 = 1e11;               
w2 = 1e10;               
w3 = 1e15;   
index = 0;
K = w1:w2:w3;
for w = 1:length(K)
    index = index + 1 ;
e(index) = e_inf - (Wp^2/K(w)^2+1i*K(w)*gamma);
f(index) = K(w);
x(index) = f(index) ;
y(index) = real(e(index));
end
semilogx(x,y, 'linewidth', 2), grid on

% It is better to use this syntax of the code:
e_inf = 11.7 ;           
Wp   = 1.0856e11;               
gamma = 2.3518e9 ;
w1 = 1e11;               
w2 = 1e10;               
w3 = 1e15;   
index = 0;
K = w1:w2:w3;
% Loop is not necessary!
e = e_inf - ((Wp^2)./K.^2+1i*K*gamma);  
f=K;
x=f;
y = real(e);
semilogx(x,y, 'linewidth',2), grid on