function y=rshift(x,dir)% dir = 0 (default)撈擱 right shift(rotate)% dir = 1撈擱 left shift(rotate)if nargin<2, dir=0; end[m,n]=size(x);if m > 1,   if n == 1,       col=1;    elseif n > 1,      error('x must be a vector! break');   end % x is a column vectorelseif m == 1,    if n == 1,       y=x; return   elseif n > 1,      col=0; % x is a row vector   endendif dir==1,  % rotate left or up   if col==0, % row vector, rotate left      y = [x(2:n) x(1)];   elseif col==1,      y = [x(2:n); x(1)]; % rotate up   endelseif dir==0, % default rotate right or down    if col==0,       y = [x(n) x(1:n-1)];   elseif col==1 % column vector      y = [x(n); x(1:n-1)];   endend