Error question :The expression to the left of the equals sign is not a valid target for an assignment

Trying to debug this loop (I am pretty new with matlab). I get the error for the last line. Any tips?

for i=2:length(text)

   roi=text{i};

eval([roi,'_sani=table2(indici_cnt,i);']);  

eval([roi,'_fep=table(indici_fep,i);']);     

eval(['table_out.',roi,'=[',roi,'_fep;',roi,'_sani];']);

end

[Ingrid]

why are you using the eval function ?

[Stephen23]

Ugh!

Using eval makes your code slow, buggy, and obfuscated.

"Any tips?"

Don't use eval!

Learn to use indexing.

[M.Gloria]

well, good question! (To be clear , I colleague of mine wrote this code and I am trying to "understand" its logic) basically I want to obtain an output table (structure) in which column vectors are concatenated (picked out from xls files). Attached you can find a screenshot of the entire function. I know the eval function is not recommended but I still have to figure out How to replace it!

[M.Gloria]

[Stephen23]

@M.Gloria: screenshots are not very useful for us. Please upload the code using the paperclip button. Then click Choose file and Attach file buttons.

Answer 1

[Stephen23]

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

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

[Jan]

@Stephen: What about posting this perfect answer as an own thread and inserting a link to it, when the next one asks for eval? This would allow us to upvote your answer enough.