How to assign a name for every result in every iteration by using for loop

Question

Abdulrahman Alotibi 2023-3-14

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1928745-how-to-assign-a-name-for-every-result-in-every-iteration-by-using-for-loop

回答： Walter Roberson 2023-3-14

HI, in the following code:

T = 85; 
Delta_T = 3;
for n = 1:15 
    T = T - Delta_T 
end

How to assign a name for every result in every iteration by using for loop, i want the result for each iteration be like, T1=, T2=, T3=, ... T15=

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Answer 1

Jan 2023-3-14

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https://ww2.mathworks.cn/matlabcentral/answers/1928745-how-to-assign-a-name-for-every-result-in-every-iteration-by-using-for-loop#answer_1193055

在 MATLAB Online 中打开

This is a really bad idea. Hiding an index in the name of a variable is a complicated method, which requires even more complicated methods to access the variables later on. See TUTORIAL: Why and how to avoid Eval.

Prefer to use an index as index:

T0      = 85; 
Delta_T = 3;
T      = zeros(1, 5);
T(1)   = T0;
for n = 2:15 
    T(n) = T(n - 1) - Delta_T; 
end

Now use T(1) instead of T1.

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Answer 2

Walter Roberson 2023-3-14

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1928745-how-to-assign-a-name-for-every-result-in-every-iteration-by-using-for-loop#answer_1193070

在 MATLAB Online 中打开

Compare:

T0 = 85; 
Delta_T = 3;
n = 1;
start = tic;
while toc(start) < 20
    eval(sprintf('T%d = T%d - Delta_T;', n, n-1));
    n = n + 1;
end
variables = who();
size(variables)
ans = 1×2
       61625           1
T = 85;
start = tic;
while toc(start) < 20
    T(end+1) = T(end) - Delta_T;
end
size(T)
ans = 1×2
           1    44186377