## Why am i getting "Unable to perform assignment because the indices on the left side are not compatible with the size of the right side"

on 10 May 2019

on 10 May 2019

### Raj (view profile)

function ydot=problem4data(W,X)
fa0=5; %mol/s
fb0=2*fa0;%mol/s
fi=2*fa0; %mol/s
ca0=2; %mol/dm^3
T1=325; %K
Ta=300; %K
T2=305;%K
Cpa= 20;%cal/molK
Cpb=Cpa;
Cpc=Cpa;
E=25; %kcal/mol
R=1.987*.001;%kcal/molK
Cpi=18; %cal/molK
Ua=320; %cal/s.m^3.K
Hrx= -20; %Kcal/mol
k2=.0002; %dm^6/kg.mol.s
alpha=.000115; %kg^-1
Cpsum=Cpa+Cpb+Cpi;
x=[0:0.1:1];%assumption
T=T1+((x.*(-Hrx))./(Cpsum));
Kc2=1000;
Kc1=Kc2.*exp((Hrx./R).*((1./T2)-(1./T)));
k1=k2.*exp((E./R).*((1./Ta)-(1./T)));
y1=1;%assumption
xenum=((3.*Kc1)./4)- sqrt(((3.*Kc1)./4)-((2.*Kc1).*((Kc1./4)-1)));%numerator xe equation
xedenom=2.*((Kc1./4)-1);%denominator xe equation
xe=xenum./xedenom;
pb= 1400; %kg/m^3
ra=-((k1.*ca0.*(T./T1).*y1).^2).*((1-x).*(2-x)-((4*x.^2)./Kc1));
rae=-((k1.*ca0.*(T./T1).*y1).^2).*((1-xe).*(2-xe)-((4*xe.^2)/Kc1));
Tnum=(Ua./pb).*(Ta-T)+(ra.*Hrx);
Tdenom=(fa0+fb0+fi).*(Cpsum);
ydot(1)=(-ra)./fa0;
ydot(2)=-rae./fa0;
ydot(3)=Tnum./Tdenom;
ydot(4)=(-alpha./(2.*y1)).*(T./T1);
ydot=ydot';
end

Chidera Agu

on 10 May 2019
x=X(1)
xe=X(2)
T=X(3)
Y=X(4)
y=p0/p
KSSV

### KSSV (view profile)

on 10 May 2019
What is W and X?? Inputs to the function.
Chidera Agu

### Chidera Agu (view profile)

on 10 May 2019
W ranges from 0 to 1000
X is what i just decided to use to represent x,xe,T,and y. (dx/dW, dT/dW, dy/dW)

on 10 May 2019