How to write a .csv file from a 1x2 cell?

Hello,

In my code I have MI={a b}, where a, b are numbers calculated by equations. MI is 1x2 cell. I would like to write MI to a csv file, But I do not know how.

Could you help me?

Answer 1

[Kojiro Saito]

This document is helpful for undestanding exporting cell array to csv files.

https://www.mathworks.com/help/matlab/import_export/write-to-delimited-data-files.html#br2ypq2-1

If you're using R2019a or later, writecell is the easiest way.

writecell(MI, 'result.csv')

If you want to add variable names (a and b) to the header of csv file, writetable is suitable.

MIt = table(a, b);
writetable(MIt, 'result.csv')

writetable is available from R2013b.

If you're using older version, fopen and fprintf are available.

MI={a b};
fileId = fopen('result.csv', 'w');
formatSpec = '%f, %f\n';
[nrows, ncols] = size(MI);
for row = 1:nrows
    fprintf(fileId, formatSpec, MI{row,:});
end
fclose(fileId);

[Ivan Mich]

ok thank you. One more question. In my code I am reading by using a loop amy files, and for each itaration I am calculating a and b, as I mentioned. I would like for each Iteration to create many .csv files, By using a loop.

Do you know how?

[Kojiro Saito]

You can write csv files in a for loop. Here is a sample which reads data*.csv and writes result*.csv files.

In this sample, it assumes data1.csv, data2.csv, ... have columns whos names are col1 and col2, then calculate a and b. Please replace the codes so that fit your actual codes.

list = dir('data*.csv');
for n=1:length(list)
    t = readtable(list(n).name);
    a = mean(t.col1);
    b = mean(t.col2);
    t2 = table(a, b);
    filename = sprintf("result%d.csv", n);
    writetable(t2, filename)
end

Or, you can do the same thing by datastore.

 ds = datastore('data*.csv');
 ds.ReadSize = 'file';
 iter = 1;
 while hasdata(ds)
     t = read(ds);
     a = mean(t.col1);
     b = mean(t.col2);
     t2 = table(a, b);
     filename = sprintf("result%d.csv", iter);
     writetable(t2, filename)
     iter = iter + 1;
 end

[Ivan Mich]

Thank you very much !!!!