MATLAB: How to save a matrix as text file

1file iofprintfMATLAB

I want to save a matrix as text file.

Each column should be separated by tab.

The output file should be read with any text editor

When the output is opened, it should display the numbers

in the same way it looks like in Matlab.

Thank you for your help

Emerson

Best Answer

One way is to use FPRINTF.

A = round(rand(6,7)*9)  % Write this to file.
fid = fopen('Mymatrix.txt','wt');
for ii = 1:size(A,1)
    fprintf(fid,'%g\t',A(ii,:));
    fprintf(fid,'\n');
end
fclose(fid)

EDIT

Changed the 'w+' to 'wt' in the FOPEN call.

If you have floating point numbers, you may want to use '%20.18f \t' instead of '%g\t' or similar. See FPRINTF for format specifiers.

Related Solutions

MATLAB: Reading big textfile with textscan

Solution One

You do not need to delete the first ten rows from the file, because textscan has an option to ignore header lines, so you can use this instead:

Out = textscan(....,'HeaderLines',10);

To read 1280 columns of data you need to define this in the format string, so the final code could be something like this:

fmt = repmat('%f',1,1280);
fid = fopen('textfile.txt','rt')
out = textscan(fid, fmt, 'Delimiter',',', 'HeaderLines',10);
fclose(fid);

Solution Two

If the data in the matrix is all numeric (note the header lines do not need to be) then you could use the much simpler dlmread instead, something a bit like this:

out = dlmread('textfile.txt',',',10,0);

Examples

% textscan
fmt = repmat('%f',1,5);
fid = fopen('temp.txt','rt');
out_txt = textscan(fid, fmt, 'Delimiter',',', 'HeaderLines',3);
fclose(fid);
out_txt = cell2mat(out_txt)
% dlmread
out_dlm = dlmread('temp.txt',',',3,0)

display this in the command window:

out_txt =
     0     1     2     3     4
     5     6     7     8     9
out_dlm =
     0     1     2     3     4
     5     6     7     8     9

The sample text file that I used is attached here:

MATLAB: Concatenate data using fgets

You are closing the file in the loop. close the file after the loop. I assume the below should work.

function read_datapattern(filename)
fid = fopen(filename,'rt');
if fid < 0
  error('error opening file %s\n\n',filename);
end
pattern = fgets(fid);
for n = 1:32767
  nextline = fgets(fid);
  pattern = strcat(pattern, nextline);
fprintf(pattern);
fprintf('\n');
end
fclose(fid);

Best Answer

Related Solutions

MATLAB: Reading big textfile with textscan

MATLAB: Concatenate data using fgets

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