How do I write a cell array of strings to a file using DLMWRITE or CSVWRITE functions in MATLAB?

I would like to write my cell array out to a delimited file, but DLMWRITE and CSVWRITE do not support it.

Answer 1

[MathWorks Support Team]

This change has been incorporated into the documentation in MATLAB 7.9 (R2009b). For previous releases, read below for any additional information:

The ability to save a cell array of strings to a text file with one function is not available in MATLAB but can be implemented in a number of methods. You will need to use low-level file I/O routines to achieve this. Depending on whether you have stored numbers or text in your cell array, you may need to modify the code below to be specific for your cell array:

fid=fopen('myFile.csv','wt');

x={'sin','cos','tan','log','exp'};

[rows,cols]=size(x)

for i=1:rows

      fprintf(fid,'%s,',x{i,1:end-1})

      fprintf(fid,'%s\n',x{i,end})

end

fclose(fid);

The same may be achieved without a loop, but using string and cell manipulation functions available in MATLAB:

fid=fopen('myFile.csv','wt');

x={'sin','cos','tan','log','exp'};

csvFun = @(str)sprintf('%s,',str);

xchar = cellfun(csvFun, x, 'UniformOutput', false);

xchar = strcat(xchar{:});

xchar = strcat(xchar(1:end-1),'\n');

fprintf(fid,xchar)

fclose(fid);

If you do have to modify any of the above code, some functions that may be helpful are: ISNAN, ISNUMERIC, ISCHAR, FPRINTF, FOPEN and FCLOSE.

You can find more information about each of these functions in the documentation. For example, to read more on ISNAN, type the following at the MATLAB command prompt:

doc isnan

or

help isnan

[Rini Varghese]

A simpler way perhaps is to set the delimiter to ''. For example: x = {'sin';'cos'}; y = cell2mat(x); dlmwrite('myfile',y,''); Note that x is separated by ; instead of , Hope this helps!