MATLAB: Tab delimited .txt file

text file

In order to write a matrix as a tab delimited .txt file I can use the following command:

dlmwrite(Filename, Data, 'delimiter', '\t');

Say that the dimensions of 'Data' is [m n], how is it possible to include a non numeric vector (i.e. vector containing words) as m(1) in order to state what each colummn refers to in the .txt file?

thanks

Best Answer

Suppose that your Data is:

Data = [1 2 3;4 5 6; 7 8 9];

Would you like to create such a file?

line1 1 2 3
line2 4 5 6
line3 7 8 9

If so, this is my suggestion:

Data = [1 2 3;4 5 6; 7 8 9];
names = {'line1','line2','line3'};
fid = fopen('test_file','w');
for k=1:3
   fprintf(fid,'%s\t%.2f\t%.2f\t%.2f\n',names{k},Data(k,:));
end
fclose(fid);

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: How to read a txt file with values and strings

Replace

A = fscanf('changing.txt','%8.1f %8.4f %8.1f %8.1f %s\r\n');

fid = fopen( 'changing.txt', 'r' );
cac = textscan( fid, '%f%f%f%f%s', 'Collectoutput',true );
[~] = fclose( fid );

where changing.txt contains

1 2 3 4 text.txt
4 3 2 1 text2.txt
1 2 3 4 text.txt
4 3 2 1 text2.txt

check output

>> cac{1}
ans =
     1     2     3     4
     4     3     2     1
     1     2     3     4
     4     3     2     1
>> cac{2}
ans = 
    'text.txt'
    'text2.txt'
    'text.txt'
    'text2.txt'

Best Answer

Related Solutions

MATLAB: Reading big textfile with textscan

MATLAB: How to read a txt file with values and strings

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