Difficulty in plotting equation in matlab

I need the MATLAB code to plot the equation

V = ((N.*k.*T_ambient./q).*(log(I./Iso)-(q.*Vgo/(N.*k.*T_ambient))) + Vgo+Rso.*I)./(1-(N.*k.*Rth.*I./q).*(log(I./Iso)-(q.*Vgo./(N.*k.*T_ambient))) - alphao.*Rso.*(I.^2).*Rth)

V should be on x axis and I on y axis. I is to be obtained using V. The values of ther variables are :

N           = 1.15; 
k           = 1.38e-23;
q           = 1.6e-19; 
Vgo         = 1.174; 
Rso         = 0.085; 
Iso         = 21.6e-15; 
alphao      = 0.0165; 
Rth         = 1;
T_ambient   = 298;

Answer 1

[Francisco J. Triveno Vargas]

Hello,

You need to create a vector or current like I = 0.01:0.1:20 Ampers,

Calculate the equation for V after plot the vector V related I

figure(10)

plot(V,I)

grid on

xlabel('Current')

ylabel(''Voltage')

[mitsuo]

I need to create vector for V and then obtain I using the equation.

[Sam Chak]

Hi @mitsuo

The vector V is automatically created when the vector I is used in the equation. Of course, if it also possible to define the equation for V first, and then creates vector I, but this 2nd method requires you to create a function handle. To avoid confusion, learn basic of plotting as shown by @Francisco J. Triveno Vargas.

I   = linspace(0, 25, 2501);
V   = ((N.*k.*T_ambient./q).*(log(I./Iso)-(q.*Vgo/(N.*k.*T_ambient))) + Vgo+Rso.*I)./(1-(N.*k.*Rth.*I./q).*(log(I./Iso)-(q.*Vgo./(N.*k.*T_ambient))) - alphao.*Rso.*(I.^2).*Rth);
plot(V, I), grid on, xlabel I, ylabel V

[Francisco J. Triveno Vargas]

Nice

Answer 2

[Walter Roberson]

N = 1.15; 
k = 1.38e-23;
q = 1.6e-19; 
Vgo = 1.174; 
Rso = 0.085; 
Iso = 21.6e-15; 
alphao = 0.0165; 
Rth = 1;
T_ambient=298;
eqn = @(V,I) V - ( ((N.*k.*T_ambient./q).*(log(I./Iso)-(q.*Vgo/(N.*k.*T_ambient))) + Vgo+Rso.*I)./(1-(N.*k.*Rth.*I./q).*(log(I./Iso)-(q.*Vgo./(N.*k.*T_ambient))) - alphao.*Rso.*(I.^2).*Rth) )

eqn = function_handle with value:
    @(V,I)V-(((N.*k.*T_ambient./q).*(log(I./Iso)-(q.*Vgo/(N.*k.*T_ambient)))+Vgo+Rso.*I)./(1-(N.*k.*Rth.*I./q).*(log(I./Iso)-(q.*Vgo./(N.*k.*T_ambient)))-alphao.*Rso.*(I.^2).*Rth))

fimplicit(eqn, [0 200 0 30])
xlabel('V'); ylabel('I')

[Francisco J. Triveno Vargas]

Nice