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Re-read the variable name

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Hello Everyone,
I have alloted 5 variable names to 5 different 15x1 matrix, for example.
ec=data(:,1);
fe=data(:,2); and so on for Co3, Ca and Na
then I am merging all the data into variable x for some calculation so we get x=15x5 matrix. Now after the calculation I get an answer which is one of 5 different 15x1 matrix. Then how to get the variable name as an answer. Like the code should tell that the answer is either ec, fe, Co3, Na or Ca. Means the code should read the variable name which I have assigned in the very starting of the code.
Thanks in advance.

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Stephen Cobeldick
Stephen Cobeldick on 16 Aug 2019
Using ec, fe, etc. variable names is most likely a red herring. Just use data directly, and then afterwards use indexing to select the names from a string array or a cell array of character vectors.
V = ["fe","ce",...]; % string array
V(idx)
Prakhar Modi
Prakhar Modi on 16 Aug 2019
Thanks for the reply. I am already usign the indexing to know the column which is the answer. But then how to get the name. Because I have mentioned 5 variable but in actual I have 17 variable.
Walter Roberson
Walter Roberson on 16 Aug 2019
Stephen's V variable can easily be extended to hold 17 names

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Accepted Answer

Walter Roberson
Walter Roberson on 16 Aug 2019
In https://www.mathworks.com/matlabcentral/answers/475899-how-to-properly-convert-variable-names-into-a-chain-of-strings-in-matlab
Bruno and I show how you can determine the name of a variable that you pass to a function.
So what you can do is put your logic into a function, and pass the variables into the function to be operated on. Then when you have calculated the index of the variable that was used, you can pass the index value to inputname() to find out what the variable name was.
Coding in this manner permits you to only write the names of the variables as references to their values, instead of doing that and creating a cell array of character vectors (or a string array) that has the variable names as quoted strings the way that Stephen shows.
This approach is not recommended; what is recommended is to use a table of names the way that Stephen shows. One advantage of using a table of names is that if you do so you are not restricted to the format of MATLAB variable names. You could for example use table entries such as 'CO2 nmol/s'

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