# how to use optimization iterative display

1 view (last 30 days)
Anushka Deshpandey on 13 Oct 2020
Commented: Ameer Hamza on 14 Oct 2020
how would i use optimization iterative display to display the value of Ein after each iteration?
clc
close all
clear all
gam = 10e-3; % damping frequency
f = 8.8e-3; % oscillator strength
eb = 11.2; % background epsilon
x = 5.0; %constant
om = 1.5; % frequency array;%frequency array om=1.4:0.001:1.6
syms hw0 k wp Ein er
V = [hw0, k ,wp, Ein, er ];
eq1=hw0 - 1i*((gam+sqrt(-(gam*gam)-(4*k*k)))/(2)); % resonant frequency
eq2=k - sqrt((wp*wp)/(1+2*eb) ); %to find resonant frequency
eq3=wp - sqrt(hw0^2+x*Ein*Ein);%plasma frequency
eq4=Ein - (eb-er)/(er+2*eb);%internal electric field
eq5=er - 1- ( ( f * wp*wp )./ (hw0*hw0-om.*om-1i.*om*gam));%reletive permittivity
eqs = matlabFunction([eq1;eq2;eq3;eq4;eq5], 'Vars', {[hw0 k wp Ein er ].'});
initialguess=[1.5; 2.5 ;1.4; 0.436 - 1i*0.00000112 ; -16.5-1i*1.06 ];
options = optimoptions('fsolve','Display','none','PlotFcn',@optimplotfirstorderopt,'MaxFunctionEvaluations',100);
sol=fsolve(eqs,initialguess,options);
hw0=sol(1);
k=sol(2);
wp=sol(3);
Ein=sol(4);
er=sol(5);

Ameer Hamza on 13 Oct 2020
Edited: Ameer Hamza on 13 Oct 2020
This shows how to print value of Ein in each iteration using OutputFcn
clc
close all
clear all
gam = 10e-3; % damping frequency
f = 8.8e-3; % oscillator strength
eb = 11.2; % background epsilon
x = 5.0; %constant
om = 1.5; % frequency array;%frequency array om=1.4:0.001:1.6
syms hw0 k wp Ein er
V = [hw0, k ,wp, Ein, er ];
eq1=hw0 - 1i*((gam+sqrt(-(gam*gam)-(4*k*k)))/(2)); % resonant frequency
eq2=k - sqrt((wp*wp)/(1+2*eb) ); %to find resonant frequency
eq3=wp - sqrt(hw0^2+x*Ein*Ein);%plasma frequency
eq4=Ein - (eb-er)/(er+2*eb);%internal electric field
eq5=er - 1- ( ( f * wp*wp )./ (hw0*hw0-om.*om-1i.*om*gam));%reletive permittivity
eqs = matlabFunction([eq1;eq2;eq3;eq4;eq5], 'Vars', {[hw0 k wp Ein er ].'});
initialguess=[1.5; 2.5 ;1.4; 0.436 - 1i*0.00000112 ; -16.5-1i*1.06 ];
options = optimoptions('fsolve','Display','none', 'OutputFcn', @outFcn, 'PlotFcn',@optimplotfirstorderopt,'MaxFunctionEvaluations',100);
sol=fsolve(eqs,initialguess,options);
hw0=sol(1);
k=sol(2);
wp=sol(3);
Ein=sol(4);
er=sol(5);
function y = outFcn(x, ~, s)
if strcmp(s, 'iter') % only print value when the current iteration finishes
fprintf('Ein=%f\n', x(4));
end
y = 0;
end

Ameer Hamza on 14 Oct 2020
No, they cannot be used in same array. I have fixed the issue with my code. Try the updated code.
Anushka Deshpandey on 14 Oct 2020
thanks a lot!!it worked
Ameer Hamza on 14 Oct 2020
I am glad to be of help!

Mario Malic on 13 Oct 2020
Edited: Mario Malic on 13 Oct 2020
Edit: Display does not return values of variables in iterations, my bad. Ameer's answer should get you what you wanted.
Go to documentations on fsolve, see the left section and find Input Arguments -> Options, find Display option and set it appropriately.