create different vector using for loop

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MUKESH KUMAR 2017-8-1

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回答： Jan 2017-8-1

I have three users named A1, A2 and A3 and each user has three appliances like A11 represent the A1's 1st appliance and A12, A13 similarly A21, A22, A23, and A31, A32, A33. I have the following matrix A11=[1 1 1 1 2]; A12=[1 2 2 2 2]; ......so on. so how can i use for loop for excessing these vectors and if these data in excel then how can we excess?

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KSSV 2017-8-1

What is this A11=[1 1 1 1 2]; ?

Stephen23 2017-8-1

Do NOT waste your time writing bad code that creates separate variables with numbered variable names: "A frequent use of the eval function is to create sets of variables such as A1, A2, ..., An, but this approach does not use the array processing power of MATLAB and is not recommended."

source: http://www.mathworks.com/help/matlab/matlab_prog/string-evaluation.html

Just use indexing: simple, fast, efficient, neat, simple, easy to understand, much less buggy, easier to debug, etc, etc, etc.

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

https://www.mathworks.com/matlabcentral/answers/143-how-do-i-make-a-series-of-variables-a1-a2-a3-a10

https://www.mathworks.com/matlabcentral/answers/57445-faq-how-can-i-create-variables-a1-a2-a10-in-a-loop

etc, etc, etc.

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Answer 1

Jan 2017-8-1

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在 MATLAB Online 中打开

Don't do this. The question is asked several times each week, and the answer is always the same. Do not hide an index in the name of a variable. Use an index instead.

Please read the linkls posted by Stephen and see also https://www.mathworks.com/help/matlab/matlab_prog/techniques-for-improving-performance.html:

 Avoid functions such as eval, evalc, evalin, and feval(fname). Use the function
 handle input to feval whenever possible. Indirectly evaluating a MATLAB expression
 from text is computationally expensive.