例6-17  nnz函數(shù)的應(yīng)用。
解：在命令窗口中輸入如下命令，并按Enter鍵確認(rèn)。
>> v=[1 2 5 9 4 1 2 6];
>> S=diag(v,-1)
S =
     0     0     0     0     0     0     0     0     0
     1     0     0     0     0     0     0     0     0
     0     2     0     0     0     0     0     0     0
     0     0     5     0     0     0     0     0     0
     0     0     0     9     0     0     0     0     0
     0     0     0     0     4     0     0     0     0
     0     0     0     0     0     1     0     0     0
     0     0     0     0     0     0     2     0     0
     0     0     0     0     0     0     0     6     0
>> NZ=nnz(S)
NZ =
     8
>> D=nnz(S)/prod(size(S))
D =
    0.0988
>>