举例：
A1=upcoef('a','cA1','db1',1,ls); D1=upcoef('d','cD1','db1',1,ls); subplot(1,2,1);plot(A1);title('Approximation A1') subplot(1,2,2);plot(D1);title('Detail D1')
Approximation A1 75 70 65 60 20 55 0 50 -20 45 40 35 30 -40 -60 -80 80 60 40 Detail D1
0
2
4
6
0
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4
6
11