Textscanning and exporting several text files

Hi,

I'm trying to combine data from several text files (file1, file2, etc.) and export the data into one file (or matrix) after textscan loops and some basic calculation. I have only managed to export from the last loop (overwrites?). My code so far:

d = dir('*.txt');
for n=1:numel(d)
    filepath=['..\matlab_testing\'];      
    filena=['file' num2str(n) '.txt'];    
[filepath filena];
if exist([filepath filena])
  fid=fopen([filepath filena],'rt');
  out = [];
row = fgetl(fid);    
data = textscan(fid, '%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f');
out = [out;cell2mat(data)];
end 

idx1 =out(:,3) == 100;
h1 = out(idx1,:);  

xlswrite('h_ka_txt.xls',h1,'klo1', 'A2'); %works, but contains data only from the last file

How to continue so that I have one matrix that contains data from all the files?

Also, is the better way to textscan than (fid, '%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f'), if file has several hundred columns?

Thank you, all the help is greatly appreciated, Liisa

Answer 1

[Chandra Kurniawan]

Hi, Liisa

Look at line

data = textscan(fid, '%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f');

Did you mean

data = textscan(row, '%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f');

And you can replace these lines

filepath=['..\matlab_testing\'];      
filena=['file' num2str(n) '.txt'];    
[filepath filena];
if exist([filepath filena])
fid=fopen([filepath filena],'rt');

with

fid = fopen(d(n).name,'rt');

Also at line

out = [];

should be placed outside the loop.

And about

data = textscan(row,'%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f');
out = [out; cell2mat(data)];

Can be replaced with

data = str2num(row);
out = [out; data];

So, the complete code is :

d = dir('*.txt');
out = [];
for n = 1 : numel(d)
    fid = fopen(d(n).name,'rt');    
    row = fgetl(fid);        
    %data = textscan(row,'%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f%f');
    data = str2num(row);
    %out = [out; cell2mat(data)];
    out = [out; data];
end

Now, just try to type out in command window and you'll get the result as 3 x 17 matrix.

I hope this helps.

Answer 2

[Liisa]

Thank you, that was very helpful and did solve my problem.