Error: Maximum recursion limit of 500 reached.

Hello all,

I am trying to run following code in MATLAB;

function dX_dt = Model(t, x)

% Initial states

Sno3_0 = 0.62;

SacT_0 = 0.6;

Xdn_0 = 0.2;

x0 = [Sno3_0; SacT_0; Xdn_0];

x = [0;0;0];

% Naming the states

Sno3 = x(1);

SacT = x(2);

Xdn = x(3);

% Model Parameters

tFinal = 120;

HRT = 6;

D = 0.166;

Sno3_in = 10;

Sac_in = 11;

X_in = 0;

%Yxac = 0.75;

Yxac = 0.3075;

%Yno3ac = 0.88;

Yno3ac = 0.9152;

pKa_ac = 4.777;

%ka_ac = 1.67109E-05;

pH = 5;

%H = 0.00001;

qmax = 0.914634146;

Ks_ac = 0.024;

Ks_no3 = 0.248;

% Algebric

Sach = SacT*10^(-pH)/(10^(-pKa_ac)+10^(-pH));

% Rate equation

Mac = (Sach/(Ks_ac+SacT));

Mno3 = (Sno3/(Ks_no3+Sno3));

qSac = qmax*min(Mac,Mno3);

% Model balances

dXdn_dt = -D*Xdn+qSac*Xdn*Yxac;

dSno3_dt = D*(Sno3_in-Sno3)-qSac*Yno3ac*Xdn;

dSacT_dt = D*(Sac_in-SacT)-qSac*Xdn;

% Returning the vector of derivatives

dX_dt = [0:0:0];

dX_dt = [dSno3_dt; dSacT_dt; dXdn_dt];

[t,x] = ode45('Model', [0:1:240],x0)

plot(t,x);

However, I am continuously getting the error of;

Error in odearguments (line 90)

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

Caused by:

Maximum recursion limit of 500 reached.

Kindly help me how to resolve this issue. Thanks

Answer 1

[Steven Lord]

Do not call ode45 with 'Model' as the first input from within Model.m itself. Move the ode45 call (and the code necessary to create the inputs with which you call ode45) to a separate file or run them in the Command Window.

[khizar hayat]

Running now. Thank You.