DFT口囗口:N=4 543210 0 0.5 1.5 2 2.5 3.5 4 DFT口口:N=4 200 100 0 -100 200 0 0.5 1.5 2 2.5 3.5 40 0.5 1 1.5 2 2.5 3 3.5 4 -1 0 1 2 3 4 5 |X(k)| DFT频频频: N=4 k 0 0.5 1 1.5 2 2.5 3 3.5 4 -200 -100 0 100 200 频 DFT频频: N=4 k