diagonal matrix

Matrix (usually square) with zero elements except on main diagonal (See also: wikipedia)


An arrangement of a set of numbers into rows and columns like this:

$\begin{bmatrix}1 & 1 & 0 \\0 & 0 & 1 \\0 & 1 & 0 \end{bmatrix}$

Each element of the matrix is referred to by subscripts, the first representing the row and the second the column. Thus A23 refers to the element in the second row, third column. More generally, Aij refers to the element in the ith row and jth column.