how can I save my error term in an array within while loop?

1 次查看（过去 30 天）
mehmet salihi
mehmet salihi 2021-6-6
评论： SALAH ALRABEEI 2021-6-6
I am trying to save my Error term within While loop for this code in a list, could you please help me
thank you
clear
close all, clc
%Defining the constants
L=1; % length
H=2; % Height
deltax=0.05
deltay=0.05
Beta=deltax/deltay
Beta2=Beta^2
jn=H/deltay % Maximum number of grid points along y
im=L/deltax % Maximum number of grid points along x
T1=100; T2=0; T3=0; T4=0; % boundary conditions
y=2:-deltay:0; x=0:deltax:L;
% initialize T_old to the initial guess values
T_old=zeros(jn+1,im+1);
% set boundary conditions
T_old(1,1:im+1)=T1; T_old(jn+1,1:im+1)=T3; T_old(2:jn+1,1)=T2; T_old(2:jn+1,im+1)=T4; T_new = T_old;
Error = 0.011; % could be any number that is greater than Errormax
Errormax=0.01;
iter=0;
while Error > Errormax
iter=iter+1;
for i=2:jn
for j=2:im
T_new(i,j)=(1/(2*(1+Beta2)))* (T_new(i-1,j)+T_new(i+1,j)+Beta2*(T_new(i,j+1)+T_new(i,j-1)) ) ;
end
end
Error = sum(sum(abs(T_old-T_new),2)) ;
T_old = T_new;
end
iter
  3 个评论
显示 1更早的评论
mehmet salihi
mehmet salihi 2021-6-6
thats sounds good, could you please tell how to save iterations also
my aim is to draw the iterations versus error history.
when i write the below command, i can see the error for each iterations,
disp([Error iter])
i want to plot them
thank you in advance
SALAH ALRABEEI
SALAH ALRABEEI 2021-6-6
the iteration starts from 1 and keeps increasing +1. So when the while iteration stops. Thus iter will be the maximum number of interations. So to plot the error,
%
plot(1:iter,error)

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

Scott MacKenzie
Scott MacKenzie 2021-6-6
编辑：Scott MacKenzie 2021-6-6
I haven't examined your code in any detail. However, if I understand your question correctly, you simply want to save all the error terms calculated in your loop in a list, probably so you can process them in some way after the loop finishes. In this case...
errorSave = [];
while ...
Error = ...
errorSave = [errorSave Error];
end
% all the computed errors are in the vector errorSave

类别

在 Help Center 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by