function b = posori(a);
%  b = posori(a);
%      Puts orientation in 0 to 2*pi interval
[m,n] = size(a);
b = zeros(m,n);
for ii = 1:m
  for jj = 1:n
    if a(ii,jj) < 0
      b(ii,jj) = a(ii,jj) + 2*pi;
    end
    if a(ii,jj) > 0
      b(ii,jj) = a(ii,jj);
    end
  end
end
