Solving DAE - Index may be greater than one.

This is my program to solve DAEs:

function btp_25Jan4

syms cm(x) Pe(x) g(x) delpie(x) Rad(x) Re Sc de Rr C0 D A B kp t Peo delp Rm Rg Mw kad n L;

eqs = [(1/(2*(cm-1)))*(g-(g^2)/5)*diff(cm,1)-(1-3*g/10)*diff(g,1)==(8/(Re*Sc*de/L))*(8-Pe*g)/(g^2),...
       Pe*cm*Rr*g + 8*(cm-1)==(de/(C0*D))*g*(A*cm/(1+B*cm))*kp*(exp(-kp*t)),...
       Pe==Peo*(1-delpie/delp)/( 1+Rad/Rm),...
       delpie==2*Rg*C0*Rr*cm/Mw,...
       Rad==kad*((A*cm/(1+B*cm))*(1-exp(-kp*t)))^n];

vars = [cm(x); Pe(x); g(x); delpie(x); Rad(x)];

Mu = 0.001;
Re = 600;
D = 1.4*(10^-9);
Sc = Mu/D;
de = (4*0.08/pi)^0.5;
Rr = 0.72;
C0 = 4*(10^-3);
A = 0.26;
B = 130;
kp = 0.58;
t = 2*3600;%2 hours
Peo = 24;
delp = 400000;
Rm = 1/(0.001*1.6*10^-11);
Rg = 8.314;
Mw = 20000;
kad = 4*(10^13);
n = 0.15;
L = 0.145;
go = (128/(3*Re*Sc*de/L))^(1/3);

[eqs, vars, ~] = reduceDifferentialOrder(eqs, vars);
[DAEs,DAEvars] = reduceDAEIndex(eqs,vars);
[DAEs,DAEvars] = reduceRedundancies(DAEs,DAEvars)

DAEs = subs(DAEs);
f = daeFunction(DAEs, DAEvars);
F = @(x, Y, YP) f(x, Y, YP);

y0est = [0; 1];% have used only 2 because after reduceRedundancies only 2 DAEvars and DAEs are left
yp0est = zeros(2,1);

opt = odeset('RelTol', 10.0^(-2), 'AbsTol' , 10.0^(-2));
[y0, yp0] = decic(F, 0.0005, y0est,[], yp0est,[], opt);
end

But I get this error

Error using decic>sls (line 170)
Index may be greater than one.

Error in decic (line 77)
    [dy,dyp] = sls(res,dfdy,dfdyp,neq,free_y,free_yp);

Error in btp_25Jan4 (line 48)
[y0, yp0] = decic(F, 0.0005, y0est,[], yp0est,[], opt);

Please help me to know where have I done the mistake. Thanks.

[akshay]

hey were you able to resolve the error

I am getting same error...don't know how to proceed

[Ghaith Salah]

Im having the same problem, kindly let me know if you resolved the error

[Ramanuja Srinivasan]

Hi, have you sorted out this problem, because i am encountering the same error. I would really appreciate your help.

Answer 1

[Szar]

Try fixing some of the initial guesses.