Not sure why I'm getting this error - Index exceeds number of array elements (0).

I'm not quite understanding why I am getting this error for the code below. I get the error

Index exceeds the number of array elements (0).

Error in importdata (line 36)
          alpha(k,1) = first_data(1);

However I only get this error when the number of files I am trying import exceeds 10. I'm guessing there is something I am missing but I can't quite put my finger on it. Can anyone suggest a way to solve it?

% Read the data from each file
  fid = fopen(fullFileName);
  
  c = 0; store = false;
    while true
      l = fgetl(fid);
        if l == -1 % Break loop
           break
        end
% while ~feof(fid)
      % Read Alpha and Beta
      if strcmp(l(1:5),'alpha') %Get row starting with alpha
          l = fgetl(fid); % get next line
          first_data = str2num(l);
          %alpha_beta(k,1:2) = first_data([1,3]); % store alpha and beta
          alpha(k,1) = first_data(1);
          beta(k,2) = first_data(3);

      end
      
      % Read matrix of data below 'Dose'
      store = strcmp(l(1:4),'Dose');
      while store
          l = fgetl(fid);
          c=c+1;
          if l == -1    % Exit and set store back to false
              store = false;
              break
          end
          data(c,:) = str2num(l);
      end
  end
  file{k} = data;
  clear data
  
  %Read 'Dose', 'SF', 'Errors' into separate cells
  dose{k} = file{k}(:,1);
  sf{k} = file{k}(:,2);
  numcol = @(x) size(x,2);
  
  if numcol(file{k}) == 3 
    errs{k} = file{k}(:,3)-sf{k};
  else 
    sfanderrs{k} = file{k}(:,3);
    errs{k} = file{k}(:,4); 
  end

end

Answer 1

[KALYAN ACHARJYA]

alpha(k) = first_data(1);
beta(k) = first_data(3);

[mel1708]

Hi Kalyan,

Thanks for your reply! Unfortunately I'm still getting the same error.

[KALYAN ACHARJYA]

Please share

>> whos first_data

[mel1708]

The purpose of first_data is to read a row of 8 values from each .dat file read. The code appears to work up until I am working with more than 10 .dat files.

  Name            Size            Bytes  Class     Attributes

  first_data      1x8                64  double 
  

I realised I didnt copy the start of the code where I am importing files with a certain sequence in the filename. The section of code below should be placed before %Read data from each file in my original question.

  % Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '*235*'); % Define desired parameters
theFiles = dir(filePattern); % List the files which satisfy these parameters
whichFile = fullfile(myFolder,{theFiles.name});
numFiles = length(theFiles);
for k = 1 : numFiles
  baseFileName = theFiles(k).name;
  fullFileName = fullfile(myFolder, baseFileName);
  fprintf(1, 'Now reading %s\n', fullFileName);
% Read the data from each file
  fid = fopen(fullFileName);
  
  c = 0; store = false;
    while true
      l = fgetl(fid);
        if l == -1 % Break loop
           break
        end