# error: Division by an OptimizationVariable not supported.

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BOWEN LI on 26 Jul 2019
Hi everyone, I met a error mentioned in my title, however, i don't think my code could be organized by a solver-based approach. (I am trying with the problem-based approach).
y=optimvar('y',[4,1,4],'Type','integer','LowerBound',0,'UpperBound',1);
yi=[y(1,1,1),y(2,1,1),y(3,1,1),y(4,1,1);y(2,1,1),y(2,1,1),y(3,1,1),y(4,1,1);y(3,1,1),y(3,1,1),y(3,1,1),y(4,1,1);y(4,1,1),y(4,1,1),y(4,1,1),y(4,1,1)]; %create binary decision variable yit
yi(:,:,2)=[y(1,1,2),y(2,1,2),y(3,1,2),y(4,1,2);y(2,1,2),y(2,1,2),y(3,1,2),y(4,1,2);y(3,1,2),y(3,1,2),y(3,1,2),y(4,1,2);y(4,1,2),y(4,1,2),y(4,1,2),y(4,1,2)];
yi(:,:,3)=[y(1,1,3),y(2,1,3),y(3,1,3),y(4,1,3);y(2,1,3),y(2,1,3),y(3,1,3),y(4,1,3);y(3,1,3),y(3,1,3),y(3,1,3),y(4,1,3);y(4,1,3),y(4,1,3),y(4,1,3),y(4,1,3)];
yi(:,:,4)=[y(1,1,4),y(2,1,4),y(3,1,4),y(4,1,4);y(2,1,4),y(2,1,4),y(3,1,4),y(4,1,4);y(3,1,4),y(3,1,4),y(3,1,4),y(4,1,4);y(4,1,4),y(4,1,4),y(4,1,4),y(4,1,4)];
qijTemp=randi(10,4); %create a 4x4 OD matrix with random volumes between 0-10
qij0=tril((qijTemp-diag(diag(qijTemp))),-1)+((tril(qijTemp-diag(diag(qijTemp)),-1))).'
r1=0.05;%annual demand growth rate
r2=0.1;%annual demand growth rate caused by the completion of rail routes
d=[0 20 30 35].';%di distance beween links 1-4. d1=0 since link 0-1 does not exist.
Hb0=0.25;% Bus headway in time period 0 (starting time period) 0.25hrs/bus
Hr0=0;% Train headway in time perid 0 (starting time period) 0 hrs/train since rail starts
ub=10;%cost of buses in \$/hour
nc=6;%number of cars per train
uc=50;%cost of rail cars in \$/car
L=500;%rail maintenance cost in \$/mile
k=1000;%rail construction cost in \$/mile
td=0.08;%dwell time for bus and rail in hours
vb=40;% bus operating speed
vr=60;% train operating speed
u=10; %user value of time in dollars per hour
N=4;
qij=zeros(4,4,N);
hb=optimexpr(4);
hr=optimexpr(4);
for t=1:N
if t==1
qij(:,:,t)=qij0;
yi(:,:,t)=zeros(4,4);
sij(:,:,t)=zeros(4,4);
else
qij(:,:,t)=qij(:,:,t-1)*(1+r1).^t*((1/8)*(1+sij(:,:,t)).^t);
end
hb(t)=2*sqrt(2*(1-yi(1,:,t))*d/vb+sum((1-yi(1,:,t))*td)*ub/(sum((1-yi(:,:,t)).*qij(:,:,t)))); %error
hr(t)=2*sqrt((2*yi(1,:,t)*d/vr+sum(yi(1,:,t)*td))*nc*uc/sum(y(:,:,t).*qij(:,:,t))); %error
end
% Thank you so much for helping me check this code. The error happened at hb(t) and hr(t)
Torsten on 26 Jul 2019
I think it would help to present your optimization problem in a mathematical notation.

Harsha Priya Daggubati on 8 Aug 2019