How can i assign certain length for each column of exported text file?

Hi,

I am trying to write a 8680*18 cell array in to a text file. But i need to assign certain defferent lenght for elements in each column (i.e. all elements in first have 3 characters and all elements in the second column have 12 characters, etc). can anyone help?

Thank you

Answer 1

[Walter Roberson]

None of the Mathworks supplied tools for writing out matrices support that, so you will need to construct it yourself.

col_widths = [3 12 etc];
fmt_cell = [sprintfc('%%%ds', col_widths), '\n'];
fmt = [fmt_cell{:}];
your_cell_transpose = your_cell.';

fid = fopen('YourFile.txt', 'wt');
fprintf(fid, fmt, your_cell_transpose{:});
fclose(fid);

[Joseph]

Thank you Walter for your answer.

I tried below script and worked for me.

import the cell array using fprintf. Open a file that you can write to named celldata.dat. Define formatSpec using the format specifiers to describe the pattern of the data in the file. Typical format specifiers include '%s'for a character vector, '%d' for an integer, or '%f' for a floating-point number. Separate each format specifier with a space to indicate a space delimiter for the output file. Include a newline character at the end of each row of data ('\n').

fileID = fopen('celldata.dat','w');
formatSpec = '%s %d %2.1f %s\n';

Determine the size of C and export one row of data at a time using the fprintf function. Then close the file. fprintf writes a space-delimited file.

[nrows,ncols] = size(C);
for row = 1:nrows
    fprintf(fileID,formatSpec,C{row,:});
end
fclose(fileID);

[Walter Roberson]

Ah, that is for mixed datatype; your question sort of implied everything was char.

Your format would have to be touched up for fixed width, such as

formatSpec = '%3s %12d %2.1f %s\n';

Note this is for right-justified in field; if you want left-justified, use a negative width, such as %-3s

[Joseph]

Thanks Walter. You are always helpful.