Update values in while loop and store values from a while loop in arrays

Question

Nnamdi Chukwunenye 2020-9-3

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/588628-update-values-in-while-loop-and-store-values-from-a-while-loop-in-arrays

评论： Neeraj Kumar 2020-9-16

Hi I am trying to run a while loop to calculate the error values. I am struggling to update the values in the while loop and then store them all. I need to store the number of iterations and all the error values per iteration while update the value of x_old to call my function again. I have my code posted below, but I can't get my values to update. Any helo would be appreciated.

% Exercise 2.1 Order of Convergence
clear
close
clc
% Define Variables
F = 12;
x_old = 0;
itr = 0;
epsilon_new = 1e30;
epsilon_target = 1e-6;
while epsilon_new > epsilon_target
    itr = itr+1;
   
    [x_new] = springcalc(F, x_old);
    epsilon_new = abs(x_new - x_old);
    eps_matrix = [epsilon_new];
    x_old = x_new;  
end
semilogy(itr, epsilon_matrix);
function [x_new] = springcalc(F, x_old)
k_0 = 30;
x_new = F/(k_0*(1+x_old^(0.1)));
end

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Answer 1

David Hill 2020-9-3

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https://ww2.mathworks.cn/matlabcentral/answers/588628-update-values-in-while-loop-and-store-values-from-a-while-loop-in-arrays#answer_489373

编辑：David Hill 2020-9-3

在 MATLAB Online 中打开

% Exercise 2.1 Order of Convergence
clear
close
clc
% Define Variables
F = 12;
x_old = 0;
itr = 0;
epsilon_new = 1e30;
epsilon_target = 1e-6;
while epsilon_new > epsilon_target
    itr = itr+1;
   
    x_new = springcalc(F, x_old);
    epsilon_new = abs(x_new - x_old);
    epsilon(itr)=epsilon_new;
    x_old = x_new;  
end
semilogy(1:length(epsilon), epsilon);
function [x_new] = springcalc(F, x_old)
k_0 = 30;
x_new = F/(k_0*(1+x_old^(0.1)));
end