Error with 'barrier' function

When I run my code, it shows:

Unrecognized function or variable 'barrier'.

Error in fmincon (line 834)

[X,FVAL,EXITFLAG,OUTPUT,LAMBDA,GRAD,HESSIAN] = barrier(funfcn,X,A,B,Aeq,Beq,l,u,confcn,options.HessFcn, ...

Error in globalMaximization (line 38)

[ optimum, fval] = fmincon(neg_target, start, [], [], [], [], xmin, xmax, [], ...

Error in ucb_choose (line 16)

optimum = globalMaximization(acfun, xmin, xmax, [guesses;xx]);

Error in add_gpopt (line 91)

optimum = ucb_choose(xx_sub, yy, KernelMatrixInv, [], ...

Error in example_addgp (line 33)

add_gpopt(f, xmin, xmax, 200, [], [], options)

I searched online, there are many problems about error in 'barrier', but nobody asked about missing function. I know that I do not have 'barrier' function, but is there any one know that how should I install it?

[KALYAN ACHARJYA]

Are you referring this function?

https://web.stanford.edu/~boyd/MTSOS/barrier.html

[Walter Roberson]

No, barrier is a Mathworks function in this context.

Answer 1

[Walter Roberson]

barrier is normally installed in toolbox/optim/optim/barrier.p

It is part of the Optimization Toolbox, which is the same toolbox as fmincon itself. barrier() is the implementation for Interior Point

Either your MATLAB path is messed up, or you need to reinstall Optimization Toolbox. (Or install it the first time if somehow you got a copy of fmincon without the toolbox)