Reading data from a text file

Hi everyone!

I have a data text file with the first four lines that look like this:

   0  {1123 13.17 4.90 3.05} {1303 13.52 9.78 6.74}
   1  
   2  {685 24.39 26.71 13.36}
   3  {685 24.33 26.60 13.78} {1045 24.31 21.47 14.67}

The first line begins with "0" followed by two sets of data enclosed by {}
The second line begins with "1" with no sets of data
The third line begins with "2" with 1 set set of data enclosed with {}
Lastly, the fourth line begins with 3 with 2 sets of data within {}

I cannot use textscan to read this data file since the format varies in each line. What I would like to do is to make it like this

For each line, I should get n by 4 matrix where n is the number of data sets enclosed by {}. Therefore I plan to have a Matlab variable C such that for each line = k, I get

for k=line
  for n=number of data sets enclosed by {}
    C{1,k}(n,4)
  end
end

As an example for C{1,1}, I should get a 2 by 4 matrix of the form

1123   13.17   4.90   3.05 
1303   13.52   9.78   6.74

Please help me how to make this work.

Thanks,

Bry

Answer 1

[Sven]

Hi Bry

This code should work just fine to do what you describe. It uses a regular expression at each line of the text file to match the "{1 2 3 4}" pattern:

fid = fopen('myFile.txt');
allMatches = cell(1000,1); % Just initialise to some large number
cellNo = 0;
tline = fgetl(fid);
while ischar(tline)
    matchedStrs = regexp(tline, '\{[^\{]*\}','match');
    if ~isempty(matchedStrs)
        cellNo = cellNo + 1;
        cellContents = cell2mat(cellfun(@(str)cell2mat(textscan(str,'{%f %f %f %f}',1)),matchedStrs','Un',0));
        allMatches{cellNo} = cellContents;
    end
    tline = fgetl(fid);
end

fclose(fid);
allMatches = allMatches(1:cellNo); % Trim off the empty cells that we initialised

[Bry S]

Sven,

I thank you very much for the answer. I havent tried it but I think it should work fine for what I need. Hoping to hear from you again should I need help.

My sincerest thanks,

Bry