how to solve this error occuring while solving ODE ''Error in ode23 (line 114) odeargumen​ts(FcnHand​lesUsed, solver_name, ode, tspan, y0, options, varargin); ''.???

[t,x] = ode45('phprocess',[0 5000],[0 0]);
Error using phprocess
Too many input arguments.

Error in odearguments (line 87)
f0 = feval(ode,t0,y0,args{:});   % ODE15I sets args{1} to yp0.

Error in ode45 (line 115)
    odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);

Answer 1

[Walter Roberson]

You have defined your function phprocess to not expect any arguments, or to only expect one argument. It needs to accept at least two arguments.

Also, using strings as the first argument to the ode*() functions became obsolete as of MATLAB 5.1, 20 years ago. You should use a function handle,

[t,x] = ode45(@phprocess, [0 5000], [0 0]);

[Steven Lord]

Actually, function handles were introduced in MATLAB 6.0 (release R12). That was around 17 years ago, I believe, since the release after that (release R12.1) came out right around when I started at MathWorks. So not 20 years, but we have recommended function handles over char vectors as the inputs to the ODE solvers for quite a while now.