Error in evalObjAndConstr (line 139)

I am doing iteration which solving a fmincon problem at each time. But then I meet this error

Operands to the || and && operators must be convertible to logical scalar values.

Error in evalObjAndConstr (line 139)

Error in sqpLineSearch (line 291)

Error in fmincon (line 915)
    [X,FVAL,EXITFLAG,OUTPUT,LAMBDA,GRAD,HESSIAN] = sqpLineSearch(funfcn,X,full(A),full(B),full(Aeq),full(Beq), ...

Error in coba_mpc1 (line 265)
    [x,fval] = fmincon(cost,x0,A,B,Aeq,Beq,lb,ub,[],options);

Where should I check for my wrong?

Answer 1

[Walter Roberson]

Your "cost" is not a function handle, or if it is a function handle, it is not returning a scalar, or you have options turned on that expect your function to return the gradient and you are not returning the expected shape.

It is difficult to be more specific without seeing your code.