load text data in matlab

Question

I have some text files (1.txt, 2.txt,..., 60.txt) and all of them have 5 lines of header. I use the following codes, but it cannot recognize the headers and import all of the data. How I can say the matlab to start importing from a specific line?

num_txt=60;
input_dir='C:\data';

filenames=dir(fullfile(input_dir,'*.txt'));
i=1;
for n=1:num_txt    
    filename=fullfile(input_dir, filenames(n).name);
    img=importdata(filename);     
    data(:,i)=img(:);
    i=i+1;
end

yuk yuk · Accepted Answer · 2013-02-25T18:48:13

IMPORTDATA has 2 additional parameters: delimiterIn and headerlinesIn.

So you use (assuming tab as a delimiter):

img=importdata(filename,'\t',5);

I'd also recommend to preallocate the data matrix.

Notice that for your code to work make sure all input files have the same size. Otherwise you will get error in data(:,n)=img(:); (yes, use n instead of i).

For above two issues you can insert into the loop:

if n==1
    data = zeros(numel(img),num_txt);
else
    assert(numel(img)==size(data,1),'sprintf('File %s has different size', filenames(n).name))
end

load text data in matlab

2 Answers