MATLAB: How to take the average of the columns of a matrix and insert into another matrix

cell arraysmatrix

I have a piece of code that reads a .txt file with several matrices and sorts them into cell arrays. Each of the matrices has always three columns with varying rows. My question would be how i can take the average of each column from these matrices separately and put it into another matrix with these averages, so that it would be a new matrix containing 3 columns, each column with the average of the column of the original matrix, and with the number of rows like the number of matrices on the .txt file. Here the code that reads the .txt file and indexed is the .txt file.
filepath = '/Users/...';
fileID = fopen(filepath);
nGroups = 0;
stationGroups = cell(0,1);
while true
    nStations = fgets(fileID);
    if ~ischar(nStations)
        break;
    end
    nGroups = nGroups + 1;
    nStations = str2num(nStations);
    stationMatrix = zeros(nStations,3);
    for currentStation = 1:nStations
        fprintf('Loading station %d of station group %d: ', ...
            currentStation, nGroups);
        testStation = fgets(fileID);
        if ~ischar(testStation)
            error('Error - file ended too early!');
        end
        testStation = str2num(testStation);
        if numel(testStation)~=3
            error('Error - Station %d didn''t have three values!', ...
                currentStation);
        end
        fprintf('%.2f ',testStation);
        fprintf('\n');
        stationMatrix(currentStation,:) = testStation;
    end
    stationGroups{end+1} = stationMatrix;
    nGroups = length(stationGroups);
end
fclose(fileID);

Best Answer

fid=fopen('file.txt');
mn=[];
while ~feof(fid)
  n=fscanf(fid,'%d',1)
  if isempty(n),break,end
  d=cell2mat(textscan(fid,'%f%f%f',n,'collectoutput',1));
  mn=[mn;mean(d)];
end
fid=fclose(fid);
While the above does dynamic reallocation for "growing" the mn array, unless and until the number of rows in the file gets to be quite large the time required is likely not going to be noticeable. If does, then preallocate mn for a large number of rows and increment a counter and fill in; remembering to check for overflow, of course.
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