Matlab: Reading from .txt file

Question

I've got a .txt file with always two values per line separated by tabs:

etc.

Always beginning with 0 0 and ending with . . (80 times)

I'd like to read all the data in with Matlab. This is my code:

% Variab
line{1} = 0;
% Open files
fid = fopen(('D:\Dokumente\Studium\8. Semester\BA\Vali mit einzelenne punkten\alle.txt'), 'rt');
% Read Data
for i = 1:80
    j = 1;
    line = fgets(fid);
    line = textscan(line,'%f %f');
    while line{1} ~= '.'
        digNum{i}(j) = line{1};
        gewicht{i}(j) = line{2};
        line = fgets(fid);
        line = textscan(line,'%f %f');
        j = j + 1;
    end
end

So as you can see I want the left number to be saved as digNum{upOneValueWhen'.'}{numberIn'Vector'} and the right number gewicht{upOneValueWhen'.'}{numberIn'Vector'}.

Everything works fine but when I get to digNum = 46 (second to the last "vector") {upOneValueWhen'.'} goes up a number. I have no idea why. 'i' should only go up after '.' but for some reason it goes up at this one particular spot.

Any ideas??? Thank you so much in advance

This looks weird line = textscan(line,'%f %f'); while line{1} ~= '.'. You cannot read a . as float with textscan. Try textscan('. .', '%f %f');. MATLAB 2015b — patrik
Thinking about it this should not be the root of your problem. It is just weird. I cannot see much else in your code which is wrong. Maybe you had something else in mind when you wrote the code. My idea is that you check the MATLAB debugger and make sure the code does what you want. — patrik

bushmills bushmills · Accepted Answer · 2016-09-06T13:31:20

I would try to read the entire file in one while loop, line by line, until the end of the file is reached:

% Open files
fid = fopen('test.txt');
% Read Data
i = 1;
j = 1;

while(~feof(fid))
    line = fgetl(fid);

    if strfind(line,'.')
        i = i + 1;
        continue;
    end;

    s = textscan(line,'%s','delimiter',' ');
    digNum{i,j} = str2double(s{1}{1});
    gewicht{i,j} = str2double(s{1}{length(s{1,1})});

    j = j + 1;

end;

fclose(fid);

Now you can easily increment i when a . is recognized.

Furthermore, making use of str2double you would be able to put all the data into two matrices.

I think the above works as mentioned.

Matlab: Reading from .txt file

2 Answers