The Circulant indexing function can be used to construct rtable objects of type Array or Matrix.

In the specification of a Matrix, if Circulant[V] is included in the calling sequence as an indexing function, where V is a Vector or list of algebraic values, a Circulant Matrix is returned.

Note:    A Circulant Matrix is a Matrix where the entries of a given row are the elements of the previous row moved cyclically one position to the right.  All entries on the main diagonal are therefore identical.

The specification is similar in the construction of an Array.

$M≔\mathrm{Matrix}\left(3\,\mathrm{shape}=\mathrm{Circulant}\left[\left[1\,2\,3\right]\right]\right)$

$M≔\left[\begin{array}{ccc}1& 2& 3\\ 3& 1& 2\\ 2& 3& 1\end{array}\right]$