MATLAB: How can i read values from text file

text file text scan

Good morning everyone. New day and one more Question too. It is about again read from text files. I take datas from device as a text file. In first Picture you see that i defined Parameters as a structure which are in s Matrix. The next step that i should do is: under these Parameters there are too many value that each column belong to one Parameter. First question how can i read values from text file (be careful there are semicoluns too)and than after i read how can i connect this numbers with Parameters.

Best Answer

Do not do this. Dynamically assigning variable names is a really bad idea in MATLAB:

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

http://www.mathworks.com/matlabcentral/answers/56124-eval-is-evil-using-variables-created-dynamically-info-retrieval

http://www.mathworks.com/matlabcentral/answers/51946-systematic-do-not-use-global-don-t-use-eval

http://www.mathworks.com/matlabcentral/answers/79281-create-a-structure-name-based-on-the-string-of-a-variable-create-fieldnames-in-this-structure

The best alternatives are to keep your data in an array (e.g. as they are returned from your file-reading function), or if you require key-value access to your data then use a structure . Structures do allow dynamic fieldnames , and this is much more robust than dynamic variables.

If you have a newer version of matlab you can also use a table , which stores the data together in one array but also allows key-name access to the columns.

Summary: use a structure or table to store your data.

Related Solutions

MATLAB: Storing variables from an array loop

While you can dynamically create variable names on the fly, it's almost never a good idea. You lose syntax checking, compiler optimisation, ease of debugging, ease of understanding the code, etc.

The best way is to store your various matrices in a cell array:

GRFdata{k} = [dataArray{1:end-1}];

Referring to these matrices afterward is simply:

m = GRFdata{n}; %replace n by the index of the matrix you want to use

If you really want to use different variable names, use eval:

eval(sprintf('GRFdata%d = [dataArray{1:end-1}]', k)); %eugh!

Accessing these matrices is then:

m = eval(sprintf('GRFdata%d', n)); %eugh!

MATLAB: Read datas with different extension in a loop

I do not understand the connection between your question and the code. But a comment:

for i=1:length(zeile{1,1})
  tmp=zeile{1,1}{i}
  tmp=strrep(tmp,'.','_dot')
  zeile{1,1}(i)=cellstr(tmp);
end

Smarter without a loop:

zeile{1} = strrep(zeile{1}, '.', '_dot');

Best Answer

Related Solutions

MATLAB: Storing variables from an array loop

MATLAB: Read datas with different extension in a loop

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