Not enough input arguments. Error in chp12ex7_b (line 3) X=y(1); T=y(2); HELP how do I fix this error?

script

clear
clc
%adibatic 
v0=[0 305];
zspan=[0 10];
[z, v]=ode45(@chp12ex7_b, zspan, v0);
Cao=0.1; dH=-6000; 
X = v(:,1); T = v(:,2); 
k=0.01*exp((5033)*(1/300-1./T)); Kc=10.*exp((dH./1.987)*(1/450-1./T));
Xeq=(2.*Cao.*Kc+1-sqrt(4.*Cao.*Kc+1))./(2.*Cao.*Kc); 
rate=-k.*((Cao.^2)*((1-X).^2)-Cao*X./Kc); 
 
plot(z, v(:,1), z, Xeq), xlabel ('Volume (dm^3)'), ylabel ('Conversion'), legend('X','Xe'), title('Adiabatic')

figure
plot(z, v(:,2)), xlabel ('Volume (dm^3)'), ylabel ('Temperature'), legend('T'), title('Adiabatic')

figure
plot(z, -rate, 'k-'), xlabel ('Volume (dm^3)'), ylabel ('rate'), title('Adiabatic')

function

function ydot = chp12ex7_b(~,y)
%input variables
X=y(1);  T=y(2); 
 
%data
Ua=0; Cao=0.1; Fao=0.2; dH=-6000; Cpo=30; Ta = 0;
 
%rate 
k=0.01*exp((5033)*(1/300-1/T)); Kc=10*exp((dH/1.987)*(1/450-1/T));
rate=-k*((Cao^2)*((1-X).^2)-Cao.*X./Kc); 
 
%Equations
ydot(1)=-rate/Fao;   ydot(2)=((rate*dH)-Ua*(T-Ta))/(Cpo*Fao);  
ydot=ydot';
end

Answer 1

[Cris LaPierre]

Your code runs (see the outputs in your original post now). Do you still see the error? If so, consider clearing your workspace (though your script does this...). Maybe restart MATLAB?