function A = rdskyline(pathname)
  A = [];

  % open specified input file
  fid = fopen(pathname, 'r');
  if (fid == -1)
    return
  end

  % read size of matrix (table)
  num = fread(fid, 1, 'double');
  if (num <= 0)
    status = fclose(fid);
    return
  end

  A = zeros(num, num);

  % loop over all columns j
  for j = 1:num
    [pos nread] = fread(fid, 2, 'double');
    if (nread ~= 2)
      status = fclose(fid);
      return
    end

    first = pos(1);
    last = pos(2);

    % read if valid indices
    if (first > 0 && last >= first)
      count = last-first+1;
      [A(first:last,j) nread] = fread(fid, count, 'double');
      if (nread ~= count)
        status = fclose(fid);
        return
      end
    end

  end

  status = fclose(fid);
end