MATLAB: How to use subs to help fmincon in optimizing integral

Question

Hi,

I am a student now and want to find an optimal solution for my profit function.

I want to use fmincon cause my variable will be more than zero. The problem is fmincon do not accept symbolic so I cannot use it.

My code for my objective function is

function b = three_var(v)
Q= v(1)
q_1=v(2)
q_2=v(3)
p=200;
w_1=100;
w_2=90;
g=40;
v=30;
W_ec1=140;  
W_ec2=130;
W_ep1=60;   
W_ep2=70
o_1=10;
o_2=11;
k=0.1;
j=0.9;
syms x;
D1 = int((W_ep1*q_1+W_ep2*q_2+p*x+v*(Q-q_1-q_2-x))*(1/300),x,700,Q-q_1-q_2)
 D2 = int((W_ep1*k*(Q-x)+W_ep2*(1-k)*(Q-x)+p*x)*(1/300),x,Q-q_1-q_2,Q)
D3 = int((p*x-(W_ec1*k*(x-Q))-(W_ec2*(1-k)*(x-Q)))*(1/300),Q,Q+q_1+q_2)
D4 = int((p*(Q+q_1+q_2)-(W_ec1*q_1+W_ec2*q_2)-g*(x-(Q+q_1+q_2)))*(1/300),x,Q+q_1+q_2,1000)
b = -(w_1*j*Q)-(w_2*(1-j)*Q)-(o_1*q_1)-(o_2*q_2)+D1+D2+D3+D4

The constraint is just Q,q_1,q_2>0

Can you guys help me with this problem?

Is there any example of how to use subs to help in this case?

Thank you very much

Answer 1

Add to the end

b = double(b);