I can't graph

Hello! I am getting the following error in my code. Can someone help me solve it please. ?

Unable to perform assignment because the indices on the left side are not compatible with the size of the right side.

Error in Resistividad (line 20)

p(index) = (k(Ne)*e*u(index)).^-1;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
u1=68.5;                  
umax=1414;                
u2=56.1;                 
Cr=9.2e16;                
Cs=3.41e20;               
alfa=0.711;               
beta=1.98;    
elec  = 1.602e-19; 
N1=1e17;
N2=1e17;
N3=1e21;
index=0;
k = N1:N2:N3;
for Ne = 1:length(k)
    index = index + 1 ;
    u(index) = u1 + ((umax-u1)/(1+(k(Ne)/Cr)^alfa)) - ((u2)/(1+(Cs/k(Ne))^beta));
    p(index) = (k(Ne)*e*u(index)).^-1;
    f(index) = k(Ne);
    x(index) = f(index) ;
    y(index) = p(index);
end 

Unrecognized function or variable 'e'.

semilogx(x,y)

Answer 1

[Image Analyst]

You need to define e. If I define it as something, like 1, it works:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
e=1;
u1=68.5;                  
umax=1414;                
u2=56.1;                 
Cr=9.2e16;                
Cs=3.41e20;               
alfa=0.711;               
beta=1.98;    
elec  = 1.602e-19; 
N1=1e17;
N2=1e17;
N3=1e21;
index=0;
k = N1:N2:N3;
for Ne = 1:length(k)
    index = index + 1 ;
    u(index) = u1 + ((umax-u1)/(1+(k(Ne)/Cr)^alfa)) - ((u2)/(1+(Cs/k(Ne))^beta));
    p(index) = (k(Ne)*e*u(index)).^-1;
    f(index) = k(Ne);
    x(index) = f(index) ;
    y(index) = p(index);
end 
semilogx(x,y)

[Walter Roberson]

It would not surprise me if the reference to e should be a reference to elec = 1.602e-19 instead.