(linear algebra) A diagonal matrix all of the diagonal elements of which are equal to 1.

(linear algebra) A matrix in which the entries outside the main diagonal are all zero.

(chemistry, physics) a technique for maintaining reactive molecules in an inert material at low temperature for spectroscopic study

(linear algebra) A square (n×n) matrix that has fewer than n linearly independent eigenvectors, and is therefore not diagonalisable.

(graph theory) A square n⨯n matrix which describes an undirected graph of n vertices by letting rows and columns correspond to vertices, letting its diagonal elements contain the degrees of corresponding vertices and letting its non-diagonal elements contain either −1 or 0 depending on whether there is or there is not (respectively) an edge connecting the pair of corresponding vertices.

(linear algebra) Matrix obtained by appending the columns of two given matrices, usually for the purpose of performing the same elementary row operations on each of the given matrices.

(linear algebra) A matrix consisting of the coefficients of the variables in a set of linear equations. The matrix is used in solving systems of linear equations.

plural of active matrix

plural of transition matrix

(linear algebra) A square matrix which is obtained from the identity matrix by a single elementary row (or column) operation.