Input arguments error on line 2

I am getting input arguments error on line 2 of the function

[Andy]

What data are you trying to pass to the function?

Does the error happen with different data?

[Ameer Hamza]

Why are you calling ode45 inside the ODEfun and using ODEfun as a function handle. This will not work and cause infinite recursion.

[drummer]

where is W being used?

Answer 1

[Stephan]

Divide your code into a function for your ode and the part for solving and plottting the results:

y0 = 0; % --> change to 1 for example to get a "non boring" solution
Wspan = [0 100];
[z, fb] = ode45(@ODEfun, Wspan, y0);
plot(z, fb(:,1));

function dYfuncvecdW = ODEfun(~, Yfuncvec)
X = Yfuncvec(1);
k = 6;
Cao = 0.2;
yao = 1/3;
Fao = 2;
% Pao = 10;  --> Value is not used
epsilon = yao*(1-2-1);
ThetaB = 2;
% alpha = 0.02; --> Value is not used
Ca = Cao*(1-X)/(1+(epsilon*X));
Cb = Cao*(ThetaB-(2*X))/(1+(epsilon*X));
ra = -k*Ca*Cb^2;
dXdW = -(ra/Fao);
dYfuncvecdW = dXdW;
end

Answer 2

[Ameer Hamza]

How are you running this function? You need to pass input aguments to get an output

out = ODEfun(0, 1)