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

cell arraydata exportfprintfmatrices

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

Best Answer

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

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  test10.txt   test2.txt    test3.txt    test4.txt    test5.txt    test6.txt    test7.txt    test8.txt    test9.txt    
  test100.txt  test20.txt   test30.txt   test40.txt   test50.txt   test60.txt   test70.txt   test80.txt   test90.txt   
  test11.txt   test21.txt   test31.txt   test41.txt   test51.txt   test61.txt   test71.txt   test81.txt   test91.txt   
  test12.txt   test22.txt   test32.txt   test42.txt   test52.txt   test62.txt   test72.txt   test82.txt   test92.txt   
  test13.txt   test23.txt   test33.txt   test43.txt   test53.txt   test63.txt   test73.txt   test83.txt   test93.txt   
  test14.txt   test24.txt   test34.txt   test44.txt   test54.txt   test64.txt   test74.txt   test84.txt   test94.txt   
  test15.txt   test25.txt   test35.txt   test45.txt   test55.txt   test65.txt   test75.txt   test85.txt   test95.txt   
  test16.txt   test26.txt   test36.txt   test46.txt   test56.txt   test66.txt   test76.txt   test86.txt   test96.txt   
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test004.txt  test015.txt  test026.txt  test037.txt  test048.txt  test059.txt  test070.txt  test081.txt  test092.txt  
test005.txt  test016.txt  test027.txt  test038.txt  test049.txt  test060.txt  test071.txt  test082.txt  test093.txt  
test006.txt  test017.txt  test028.txt  test039.txt  test050.txt  test061.txt  test072.txt  test083.txt  test094.txt  
test007.txt  test018.txt  test029.txt  test040.txt  test051.txt  test062.txt  test073.txt  test084.txt  test095.txt  
test008.txt  test019.txt  test030.txt  test041.txt  test052.txt  test063.txt  test074.txt  test085.txt  test096.txt  
test009.txt  test020.txt  test031.txt  test042.txt  test053.txt  test064.txt  test075.txt  test086.txt  test097.txt  
test010.txt  test021.txt  test032.txt  test043.txt  test054.txt  test065.txt  test076.txt  test087.txt  test098.txt  
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