##### 22.6.2.28 spdiag

— Loadable Function: spdiag (v, k)

> Return a diagonal matrix with the sparse vector v on diagonal k. The second argument is optional. If it is positive, the vector is placed on the k-th super-diagonal. If it is negative, it is placed on the -k-th sub-diagonal. The default value of k is 0, and the vector is placed on the main diagonal. For example,

>               spdiag ([1, 2, 3], 1)
>               ans =

>               Compressed Column Sparse (rows=4, cols=4, nnz=3)
>                 (1 , 2) -> 1
>                 (2 , 3) -> 2
>                 (3 , 4) -> 3

> See also: diag.