ode23s problem with input arguments

I always seem to have difficulty understanding how to arrange input arguments for a system with two differential equations.

The error codes that I am receiving are that I have

1) Too many input arguments

2) Error in odearguments (line 90) f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.

3) Error in ode23s (line 121) = odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);

Thank you for the help and I wish to understand how to debug this error.

Answer 1

[Asad Mirza]

A very trivial mistake. ODE45 requires that the inputs to your function be both t and Y, even if you never plan on using t.

%This function computes the concentration of reactant A and temperature 
%profile of an endothermic CSTR. 
function r = CSTRHW4(t,Y) 
 %% stuff
end

Also it is highly suggested you do not use

clear all

Instead, just use the normal clear. Calling clear all decreases code performance, and is usually unnecessary. For more information, see the Tips section.

Answer 2

[Matthew Tom]

Thank you so much for your time! I always feel obligated to correct those nitpicky error messages that are displayed, especially those that say, "the variable isn't being used."

[Asad Mirza]

Ah yes I know those well. Even though MATLAB is intelligent sometimes at the end of the day we have to make the judgement call on its suggestions. In this case it was one where ignoring MATLAB's suggestions would have saved you some time.

Glad to see your issue was fixed!