Index exceeds the number of array elements in ODE using anonymous function

I dont't understand what is wrong with this scirpt. For different set of equations I was able to use anonymous functions inside ODE handle and everuthing was just perfect, but now, in much larger system, I am constantly getting this error

Index exceeds the number of array elements (34).

Error in full_DAO>@(t,x)[1/L1*(.............

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

Error in ode15s (line 150) odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);

Error in full_DAO (line 118) [t,sol] = ode15s(deq,[0 100e-6],zeros(1,34));

Do you have idea what can be wrong? Clearly, number of equations is 34 and nowhere I am calling higher index so I don't get it. How to avoid this error?

clear
close all
clc

format shorteng

m = 0.6;

L1 = 40e-6;
L2 = 40e-6;
L3 = 125e-9;
L4 = 125e-9;
L5 = 125e-9;
L6 = 40e-6;
L7 = 40e-6;
L8 = 125e-9;
L9 = 125e-9;
L10 = 40e-6;
L11 = 40e-6;
L12 = (1/2 + m/2)*125e-9;
L13 = (1/2 + m/2)*125e-9;
L14 = 40e-6;
L15 = 40e-6;
L16 = 125e-9*(1 - m^2)/(2*m);
L17 = 125e-9*(1 - m^2)/(2*m);

U1 = -2;
U2 = 3;
U3 = 7;
Udd = 11;

Ru1 = 100;
Ru2 = 60;
Ru3 = 20;
Rudd = 7;
R1 = 50;
R2 = 50;

%RF loss modelling
Rc3 = 1e9;
Rc4 = 5e3;
Rc7 = 200e3;
Rc8 = 500e3;
Rc11 = 15e3;
Rc12 = 700e3;
RL3 = 5;
RL4 = 2;
RL5 = 7;
RL8 = 3;
RL9 = 5;
RL13 = 5;
RL12 = 4;

C1 = 10e-9;
C2 = 10e-9;
C3 = 50e-12;
C4 = 50e-12;
C5 = 10e-9;
C6 = 10e-9;
C7 = 50e-12;
C8 = 50e-12;
C9 = 10e-9;
C10 = 10e-9;
C11 = 50e-12;
C12 = 50e-12;
C13 = 10e-9;
C14 = m/2*50e-12;
C15 = 10e-9;
C16 = m/2*50e-12;
C17 = 10e-9;

%%% Shockley diode equation
Is = 1e-14;
k = 1.38e-23;
q = 1.602e-19;
T = 300;
Vt = k*T/q;
id = @(x) 0*Is*(exp(x/Vt) - 1);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

deq = @(t,x) [...
   1/L1*(U1 - x(1)*Ru1 - x(2));
   1/C1*(x(1) - x(3));
   1/L2*(x(2) - (x(4)/C2 + x(6)));
   x(3) - id(x(4)/C2 + x(6));
   1/L3*(x(8) - x(5)*RL3 - x(6));
   1/C3*(x(5) - x(7) + (x(3) - id(x(4)/C2 + x(6))) - x(6)/Rc3);
   1/L4*(x(6) - x(14) - x(7)*RL4);
   1/C4*(x(9) - x(5) - x(8)/Rc4);
   1/L5*(x(16) - x(9)*RL5 - x(8));
   1/C5*(x(11) - x(13));
   1/L6*(U2 - x(11)*Ru2 - x(10));
   x(13) - id(x(12)/C6 + x(14));
   1/L7*(x(10) - (x(12)/C6 + x(14)));
   1/C7*(x(7) - x(15) + (x(13) - id(x(12)/C6 + x(14))) - x(14)/Rc7);
   1/L8*(x(14) - x(22) - x(15)*RL8);
   1/C8*(x(17) - x(16)/Rc8 - x(9));
   1/L9*(x(24) - x(17)*RL9 - x(16));
   1/C9*(x(19) - x(21));
   1/L10*(U3 - x(19)*Ru3 - x(18));
   x(21) - id(x(20)/C10 + x(22));
   1/L11*(x(18) - (x(20)/C10 + x(22)));
   1/C11*(x(15) - x(23) - x(22)/Rc11 + (x(21) - id(x(20)/C10 + x(22))));
   1/L12*(x(22) - (x(34)/C17 + (x(23) - x(33))*R2) - x(23)*RL12);
   1/C12*(-x(29) - x(25) - x(17) - x(24)/Rc12);
   1/L13*(x(24) - (x(30)/C15 + (x(25) - x(31))*R1) - x(25*RL13));
   x(29) - x(27);
   1/L14*(x(26)/C13 - x(27)*Rudd - Udd);
   x(31);
   1/L15*(x(24) - x(26)/C13);
   x(25) - x(31);
   1/L16*(x(30)/C15 + (x(25) - x(31))*R2 - x(28)/C14);
   x(33);
   1/L17*(x(34)/C17 + (x(23) - x(33))*R2 - x(32)/C16);
   x(23) - x(33);
];

[t,sol] = ode15s(deq,[0 100e-6],zeros(1,34));

figure(1)
plot(t,sol)

Answer 1

[Star Strider]

There’s a typo:

1/L13*(x(24) - (x(30)/C15 + (x(25) - x(31))*R1) - x(25*RL13));

↑ ← HERE

Correct that:

1/L13*(x(24) - (x(30)/C15 + (x(25) - x(31))*R1) - x(25)*RL13);

and it works!

format shorteng

m = 0.6;

L1 = 40e-6;
L2 = 40e-6;
L3 = 125e-9;
L4 = 125e-9;
L5 = 125e-9;
L6 = 40e-6;
L7 = 40e-6;
L8 = 125e-9;
L9 = 125e-9;
L10 = 40e-6;
L11 = 40e-6;
L12 = (1/2 + m/2)*125e-9;
L13 = (1/2 + m/2)*125e-9;
L14 = 40e-6;
L15 = 40e-6;
L16 = 125e-9*(1 - m^2)/(2*m);
L17 = 125e-9*(1 - m^2)/(2*m);

U1 = -2;
U2 = 3;
U3 = 7;
Udd = 11;

Ru1 = 100;
Ru2 = 60;
Ru3 = 20;
Rudd = 7;
R1 = 50;
R2 = 50;

%RF loss modelling
Rc3 = 1e9;
Rc4 = 5e3;
Rc7 = 200e3;
Rc8 = 500e3;
Rc11 = 15e3;
Rc12 = 700e3;
RL3 = 5;
RL4 = 2;
RL5 = 7;
RL8 = 3;
RL9 = 5;
RL13 = 5;
RL12 = 4;

C1 = 10e-9;
C2 = 10e-9;
C3 = 50e-12;
C4 = 50e-12;
C5 = 10e-9;
C6 = 10e-9;
C7 = 50e-12;
C8 = 50e-12;
C9 = 10e-9;
C10 = 10e-9;
C11 = 50e-12;
C12 = 50e-12;
C13 = 10e-9;
C14 = m/2*50e-12;
C15 = 10e-9;
C16 = m/2*50e-12;
C17 = 10e-9;

%%% Shockley diode equation
Is = 1e-14;
k = 1.38e-23;
q = 1.602e-19;
T = 300;
Vt = k*T/q;
id = @(x) 0*Is*(exp(x/Vt) - 1);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

deq = @(t,x) [...
    1/L1*(U1 - x(1)*Ru1 - x(2));
    1/C1*(x(1) - x(3));
    1/L2*(x(2) - (x(4)/C2 + x(6)));
    x(3) - id(x(4)/C2 + x(6));
    1/L3*(x(8) - x(5)*RL3 - x(6));
    1/C3*(x(5) - x(7) + (x(3) - id(x(4)/C2 + x(6))) - x(6)/Rc3);
    1/L4*(x(6) - x(14) - x(7)*RL4);
    1/C4*(x(9) - x(5) - x(8)/Rc4);
    1/L5*(x(16) - x(9)*RL5 - x(8));
    1/C5*(x(11) - x(13));
    1/L6*(U2 - x(11)*Ru2 - x(10));
    x(13) - id(x(12)/C6 + x(14));
    1/L7*(x(10) - (x(12)/C6 + x(14)));
    1/C7*(x(7) - x(15) + (x(13) - id(x(12)/C6 + x(14))) - x(14)/Rc7);
    1/L8*(x(14) - x(22) - x(15)*RL8);
    1/C8*(x(17) - x(16)/Rc8 - x(9));
    1/L9*(x(24) - x(17)*RL9 - x(16));
    1/C9*(x(19) - x(21));
    1/L10*(U3 - x(19)*Ru3 - x(18));
    x(21) - id(x(20)/C10 + x(22));
    1/L11*(x(18) - (x(20)/C10 + x(22)));
    1/C11*(x(15) - x(23) - x(22)/Rc11 + (x(21) - id(x(20)/C10 + x(22))));
    1/L12*(x(22) - (x(34)/C17 + (x(23) - x(33))*R2) - x(23)*RL12);
    1/C12*(-x(29) - x(25) - x(17) - x(24)/Rc12);
%     1/L13*(x(24) - (x(30)/C15 + (x(25) - x(31))*R1) - x(25*RL13));
    1/L13*(x(24) - (x(30)/C15 + (x(25) - x(31))*R1) - x(25)*RL13);
    x(29) - x(27);
    1/L14*(x(26)/C13 - x(27)*Rudd - Udd);
    x(31);
    1/L15*(x(24) - x(26)/C13);
    x(25) - x(31);
    1/L16*(x(30)/C15 + (x(25) - x(31))*R2 - x(28)/C14);
    x(33);
    1/L17*(x(34)/C17 + (x(23) - x(33))*R2 - x(32)/C16);
    x(23) - x(33);
    ];

[t,sol] = ode15s(deq,[0 100e-6],zeros(1,34));

figure(1)
plot(t,sol)

.

[jf]

Oh god. You sir are genius...as always :)

[jf]

Also just in case that I encounter it again, how did you spot it? By stepping into ode solver?

[Star Strider]

‘Oh god. You sir are genius...as always :)’

Thank you!

‘Also just in case that I encounter it again, how did you spot it? By stepping into ode solver?’

No. I just looked for subscript references that didn’t look right, and since I wasn’t concerned with anything else (syntax and other problems), it was relatively easy to detect.

I did it here in the online Run feature, however doing it offline on my computer could have thrown a line-specific error that would have made it easier to detect. Had I kept getting errors of various types, I might have done that. Fortunately, that wasn’t nbecessary.

.