Export of Cell-Arrays to more than one txt-file

Have a Cell Array XX with the dimension of 31 * 10 and each XX{i,j} consists of 1000 rows and 31 columns. These 1000 lines and 31 columns should end up in a respective txt-file.

For this I have tried to:

save(file_name_xc,'XX','-ascii');

header = '%alb_newsnow alb_oldsnow alb_decrease alb_firn alb_ice alb_shallowpack_ice alb_shallowpack_rock crit_swe_newsnow crit_swe_shallowpack snow_cf temp_wetbulb_lthr temp_wetbulb_uthr clmaxn slope_min slope_max slope_cf curv_max cwh_snow cwh_firn cch refree n_snow k_snow n_firn k_firn n_ice k_ice n_rock k_rock n_soil k_soil';

formattype = '' ; for i=1:M-1; formattype = [ formattype '%g\t' ]; end; formattype = [ formattype '%g\n' ];
% open the file with status write
fid = fopen(file_name_xc,'w')  ;
% write the header
fprintf(fid,'%s\n',header);
% write -> cell-string
 [nrows,ncols] = size(XX);
for row = 1:nrows
 fprintf(fid,formattype,XX);
end

fclose(fid);

The following error message appeared:

Warning: Attempt to write an unsupported data type to an ASCII file. Variable 'XX' not written to file. > In write_to_file at 209

Line 209 includes the code save(file_name_xc,'','-ascii).

Based on this, I tried to convert the cell-array into a matrix before I used the save(...), with

XX = cell2mat(XX);

In this case, all rows and columns are written to a single matrix and to a single txt file.

How can one write each XX {} into a separate txt-file, which consists of 1000 lines and 31 columns?

Thanks

[Jan]

Please do not cross-post a question in multiple forums. This wastes the time of the persons, who want to help you. If you have a really good reasons for cross-posting, please insert at least a link to the other threads. Thanks.

Answer 1

[Guillaume]

Well, yes, that first line you show will cause an error since you attempt to write the whole cell array (the 310 matrices) into a single file, and matlab does not know how to do this.

Nowhere in your code is there a loop to go over each of the files you want to write, so I'm a bit unclear why you expected any of it to work.

Considering that there are a lot more efficient tools than fprintf to write a matrix all at once into a text file, this is how I'd do it:

columnnames = {'alb_newsnow', 'alb_oldsnow', 'alb_decrease', 'alb_firn', 'alb_ice', 'alb_shallowpack_ice', 'alb_shallowpack_rock', 'crit_swe_newsnow', 'crit_swe_shallowpack', 'snow_cf', 'temp_wetbulb_lthr', 'temp_wetbulb_uthr', 'clmaxn', 'slope_min', 'slope_max', 'slope_cf', 'curv_max', 'cwh_snow', 'cwh_firn', 'cch', 'refree', 'n_snow', 'k_snow', 'n_firn', 'k_firn', 'n_ice', 'k_ice', 'n_rock', 'k_rock', 'n_soil', 'k_soil'};
folder = 'C:\somewhere';
nameprefix = 'somename';

for col = 1:size(XX, 2)   %note that XX is a completely useless name
   for row = 1:size(XX, 1)
      fullpath = fullfile(folder, sprintf('%s_%02d_%02d.txt', nameprefix, row, col));  %build file name however you want
      temptable = array2table(XX{row, col}, 'VariableNames', columnnames);  %convert matrix to table
      writetable(temptable, fullpath, 'Delimiter', 'tab');  and write into file in one go
   end
end

[Glazio]

How would you solve this in Matlab R2012a, when writetable and array2table isn't implemented?

[Guillaume]

Best way to solve it would be to upgrade to a newer version. Failing that, then yes, you do need to use more low level functions. This may work (untested):

for col = 1:size(XX, 2)   %note that XX is a completely useless name
   for row = 1:size(XX, 1)
      fullpath = fullfile(folder, sprintf('%s_%02d_%02d.txt', nameprefix, row, col));  %build file name however you want
      fid = fopen(fullpath, 'wt');
      fprintf(fid, '%s\n', strjoin(columnnmes, '\t'));
      fclose(fid);
      dlmwrite(fullfile, XX{row, col}, '-append', 'delimiter', '\t');  
   end
end

edit: and you probably don't have strjoin either. This implementation should work:

function joinedstrings = strjoin(strings, separator);
   strings = [strings(:), repmat({separator}, numel(strings), 1)]';
   joinedstrings = [strings{1:end-1}];
end

[Glazio]

Thanks,

The following warning/error message appears:

Attempt to execute SCRIPT strings as a function: C:\Program Files (x86)\MATLAB\R2012a Student\toolbox\matlab\strfun\strings.m

if I try to run the code:

function joinedstrings = strjoin(strings, separator); %makes the error
   strings = [strings(:), repmat({separator}, numel(strings), 1)]';
   joinedstrings = [strings{1:end-1}];
end

What could be the problem?

[Guillaume]

Did you save the function in its own m file?

[Glazio]

No, I saved the function within the Command Window.

Now, the following error message: Error using fullfile (line 25) Not enough input arguments.

occurs within the context of:

dlmwrite(fullfile, XX{row, col}, '-append', 'delimiter', '\t');

What could be the problem here?

Thanks

[Stephen23]

"No, I saved the function within the Command Window."

What does that mean?

[Glazio]

Means, I let run the function strjoin within the command window and didn't write it in an own m-file.

The current error message is related to the following code:

dlmwrite(fullfile, XX{row, col}, '-append', 'delimiter', '\t');

Especially with fullfile.

[Glazio]

I think the problem is solved. I have replaced the fullfile in dlmwrite() with fullpath, and now the txt-files are written.

Thanks for all the help

[Guillaume]

Yes, I made a typo, that fullfile in dlmwrite was indeed meant to be fullpath.