Piecewise function in a DAE

Hello, please can you help me with the following question:

I've been working in a code (m. file) , a DAEs problem , the code is long, but summarizing , I have a picewise function and I tried to include the picewise according to: https://la.mathworks.com/matlabcentral/answers/408447-how-to-include-a-piecewise

But i got the following error:

Index in position 1 exceeds array bounds (must not exceed 7).

Error in DAEs3 (line 8)

DUst = in2(8,:);

Please anyone can tell me what Im doing wrong, Thank you!!!

Here is the code:

syms t Us(t) Rs(t) HComb(t) Ms(t) MCO2(t) MCaO(t) Mg(t) Tg(t) Ts(t) Tw(t) Tm(t) g(t) yee(t) dAGSdz1(t) dAGWdz1(t) dAWSdz1(t) Dh1(t) AG1(t)

%Code ........

emi_CO2=piecewise(0<=Tg<1300, 0.2, 1300<=Tg<=4300, 0.3);

emi_H2O=piecewise(0<=Tg<1300, 0.15, 1300<=Tg<=4300, 0.12);

emiG=emi_CO2+emi_H2O-emi_CO2.*emi_H2O ;

K=(1-emiG).*(1-emiW).*(fiWS.*(1-emiG).*(1-emiS)+(1-fiWS));

emiWS=(emiW.*emiS.*(1-emiG))./(1-K);

emiGS=(emiG.*emiS.*(1+fiWS.*(1-emiW).*(1-emiG)))./(1-K);

emiGW=(emiG.*emiW.*(1+fiWS.*(1-emiS).*(1-emiG)))./(1-K);

%more code

eqs=[diff(Us(t),t)==((((pgi-PCO2g).*kCaCO3.*6.*((1-Us(t)).^(2./3)))./(xCO2ks.*rhoks1.*RCO2.*Ts(t).*dp.*wp)))

diff(Rs(t),t)==diff(Us(t),t).*(leyCaCO3/100).*Mks1.*xCO2ks.*deltahCO2

diff(HComb(t),t)==Fbr1.*huBr.*(diff((1-exp(-a.*(t-L1).^b)),1))

%more equations]

vars=[Us(t), Rs(t), HComb(t), Tg(t), Ts(t), Tw(t), Tm(t), Ms(t), MCO2(t), MCaO(t), Mg(t)];

origVars = length(vars)

origeqns = length(eqs)

M = incidenceMatrix(eqs, vars)

[eqns, vars] = reduceDifferentialOrder(eqs, vars)

isLowIndexDAE(eqs,vars)

[DAEs,DAEvars] = reduceDAEIndex(eqs,vars)

[DAEs,DAEvars] = reduceRedundancies(DAEs,DAEvars)

pDAEs = symvar(DAEs)

pDAEvars = symvar(DAEvars)

extraParams = setdiff(pDAEs, pDAEvars)

ff = daeFunction(DAEs, DAEvars, g(t), yee(t), dAGSdz1(t), dAGWdz1(t), dAWSdz1(t), Dh1(t), AG1(t),'file','DAEs3.m');

g=@(t) interp1(ft,f,t);

yee=@(t) interp1(ft,ye,t);

AG1=@(t) interp1(ft,AG,t);

dAGSdz1=@(t) interp1(ft,dAGSdz,t);

dAGWdz1=@(t) interp1(ft,dAGWdz,t);

dAWSdz1=@(t) interp1(ft,dAWSdz,t);

Dh1=@(t) interp1(ft,Dh,t);

F=@(t,Y,YP) ff(t,Y,YP,g(t),yee(t),dAGSdz1(t), dAGWdz1(t), dAWSdz1(t), Dh1(t), AG1(t));%,'file','DAEs3.m');

t0 = 0;

y0est = [0.25;0.25*Mks1.*xCO2ks.*deltahCO2;Fbr1.*huBr;Tgas+273.15;1110;Tsol+273.15;370];

yp0est= [0;0;0;0;0;0;0];

[tSol, ySol]=ode15i(F, [t0:1:L1], y0est, yp0est)