Quincunx matrix

In mathematics, the matrix


 * $$\begin{pmatrix}

1 & -1 \\ 1 & 1 \end{pmatrix}$$

is sometimes called the quincunx matrix. It is a 2&times;2 Hadamard matrix, and its rows form the basis of a diagonal square lattice consisting of the integer points whose coordinates both have the same parity; this lattice is a two-dimensional analogue of the three-dimensional body-centered cubic lattice.