MATLAB: Linprog inconsistent messages I am using linprog, and not supplying initial starting value, i.e., the code reads as follows options = optimoptio​ns(‘linpro​g’,’Algori​thm’,’inte​rior-point​’,’Display​’,’iter’); x = linprog(f,​A,b,Aeq,be​q,lb,ub,op​

Question

I am using linprog, and not supplying initial starting value, i.e., my code reads as follows

options = optimoptions('linprog','Algorithm','interior-point','Display','iter');
x = linprog(f,A,b,Aeq,beq,lb,ub,options);

I get this error Error using linprog (line 144) LINPROG requires the following inputs to be of data type double: 'X0'.

However, when I do provide a starting point then I get the following message

"The interior-point algorithm uses a built-in starting point; ignoring supplied X0."

I am confused as to what is happening.

Answer 1

You are using a version of MATLAB that requires an x0 input. Yet not all the linprog algorithms accept x0. I suggest that you pass [] as the x0 input, such as

x = linprog(f,A,b,Aeq,beq,lb,ub,[],options)

Alan Weiss

MATLAB mathematical toolbox documentation