6-17  nnzӦá
⣺Enterȷϡ
>> 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
>>
