A = rand(81,81,81);n = 20;A1 = A(:,:,n); % 81*81 二维A2 = A(:,n,:); % 81*1*81 三维A3 = A(n,:,:); % 1*81*81 三维% 将三维转为 81*81 二维A22 = reshape(A2,81,81);A32 = reshape(A3,81,81);
