display parameter values at each iteration in the optimization

Hello all,

I use "fminsearch" for optimization. I want to display or save the parameter values (x values) at each iteration. Setting 'display' 'iter' in the options only shows the function values. I was wondering how can I display or save the x values at each iteration?

I appreciate your help.

Best, Mona

[Sheng Liu]

hi，I think we have the same problem in the filed of optimization in current study,shall we change our MSN to communicate freely and quickly?

My ID:

[e-mail]

thank you

Answer 1

[Walter Roberson]

Use an OutputFcn in the options structure.

[Mona]

Thank you.

Answer 2

[Sheng Liu]

I rewrite the example in the help page of outputFcn,like this:

function [x fval] = myproblem1(x0) options = optimset('OutputFcn', @myoutput,'Display','iter'); 

[x fval] = fminsearch(@objfun, x0,options); 

function stop = myoutput(x,~,state) 

stop = false; 

if state == 'iter' 

disp([' x = ',num2str(x)]); 

end 

end 

function z = objfun(x) 

z = exp(x(1))*(4*x(1)^2+2*x(2)^2+x(1)*x(2)+2*x(2)); 

end 

end

wish it helpful for you!

[yem]

hi sheng i want to minimise a system with 2 delays a help please