Create variables from xlsx-file.

I have a MATLAB script where I load data from an xlsx-file, using 'xlsread(filename,sheet,xlRange)'. However this gives me the data in cells. I want to turn these into variables. I tried a loop using cell2mat but this didn't work:

[subsetA,y] = xlsread(filename,sheet,xlRange);
N           = length(y(:,1));
y1=zeros(1,N);
for i=1:N
    y1(i) = y{i,1};
end

Doesn't work.... Any suggestions?

[Stephen23]

"Any suggestions?"

Read this:

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

Answer 1

[Carl]

See the documentation on "xlsread" here:

http://www.mathworks.com/help/matlab/ref/xlsread.html

You can see that the second returned value (in your case, "y") is the text fields in a cell array. When you index with the {} brackets, what gets returned is a char array representation of that text. In your code, you are trying to set this char array into a numerical value (y1 is a double array). The data types are conflicting, so this does not work. I would recommend keeping the cell array representation returned by xlsread, as this is the easiest way to store/access strings that differ in length.

I would also like to second Stephen's comment. If it's true that you would like to create variables named after strings in your spreadsheet, I would highly recommend rethinking the design of your code. Stephen's link gives a great tutorial on alternatives.

Answer 2

[Guillaume]

Matlab has had readtable for over two years now. It's a lot more powerful than xlsread, can read the header of your excel data if there is one, and nicely create variables as columns of a table rather than a cumbersome cell array. Ditch xlsread (assuming you're not stuck on an ancient version).

mytable = xlsread('someexcelfile.xlsx');
%if column has header 'Total':
mytable.Total  %return values of column 'Total'

easy peasy.