Involve fminbnd in optimoptions

I want to minimize a function f: which has a single variable θ. I want to minimize the function so I want to use the command "fminbnd". Although I want to see the iteration display through "optimoptions". If I write a chunk of code like this

fun = @(theta) optimum_theta(alpha,snr_db(isnrdb),t_min,t_max,m,theta);

options = optimoptions('fminbnd','Display','iter'); % show iterations

[x fval exitflag output] = fminbnd(fun,lower_bound,upper_bound,options);

Here the chunk of code I am not getting how to proceed

Answer 1

[John D'Errico]

Note that fminbnd is not provided as part of the optimization toolbox. As well, fminbnd has been around a long time. So optimoptions does not support fminbnd. (I suppose there are good arguments as to why it should. But it apparently does not.)

Use optimset instead.

fun = @(x) (x-pi).^2; % not very creative
opts = optimset('fminbnd');
opts.Display = 'iter';
[x fval exitflag output] = fminbnd(fun,0,10,opts)

 
 Func-count     x          f(x)         Procedure
    1        3.81966     0.459775        initial
    2        6.18034      9.23398        golden
    3        2.36068     0.609825        golden
    4        3.14159            0        parabolic
    5        3.14163  1.11423e-09        parabolic
    6        3.14156  1.11423e-09        parabolic
 
Optimization terminated:
 the current x satisfies the termination criteria using OPTIONS.TolX of 1.000000e-04 

x = 3.1416

fval = 0

exitflag = 1

output = struct with fields:
    iterations: 5
     funcCount: 6
     algorithm: 'golden section search, parabolic interpolation'
       message: 'Optimization terminated:↵ the current x satisfies the termination criteria using OPTIONS.TolX of 1.000000e-04 ↵'

Note: you would have learned that quickly had you read the docs for fminbnd, where you would see that it uses optimset.

[Sudhir Kumar]

Thank you so much @John D'Errico for your explanation.