How do I import data files to column vectors in a loop?

Hello,

I'm trying to import some data from different .xlsx files into column vectors in Matlab. All files look the same, only the values are different.

Right now Matlab only shows me one vector of each (A,B,C,D,..). I need to have the vectors A,B,C,.. for all files that I read. For example A1,A2,A3,B1,B2,B3,...

Can anyone help me?

Thanks in advance!

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In the code below I make use of a Matlab generated code to import the file into a column vector.

numFiles = 3;
range = 'A1:G100';
sheet = 1;

for fileNum = 1:numFiles
    fileName = sprintf('document%1d.xlsx',fileNum);
    [A,B,C,D,E,F,G] = importfile(fileName,sheet,range);
end

Answer 1

[Michael Haderlein]

I don't know your importfile function, but in general you can do it the following way:

for fileNum = 1:numFiles
    fileName = sprintf('document%1d.xlsx',fileNum);
    [A(:,fileNum),B(:,fileNum),C(:,fileNum),D(:,fileNum),E(:,fileNum),F(:,fileNum),G(:,fileNum)] = importfile(fileName,sheet,range);
end

[Eveline]

Thanks a lot, this helped me out! :)

Answer 2

[Stephen23]

Save the data in cell arrays like this:

numFiles = 3;
range = 'A1:G100';
sheet = 1;

for k = 1:numFiles
    fileName = sprintf('document%1d.xlsx',k);
    [A{k},B{k},C{k},D{k},E{k},F{k},G{k}] = importfile(fileName,sheet,range);
end

You can access the data using the same cell array indexing, e.g. to refer to the A data from the fourth file use this:

A{4}

In case you were wondering, it is considered poor practice to dynamically name variables like name1, name2, name3, etc. See this for an explanation of why:

http://de.mathworks.com/matlabcentral/answers/180604-loop-on-dynamic-variable

[Eveline]

Thanks, but I'd rather like to stick to the column vectors