Matrix Theory

A block diagonal matrix has square submatrices along its diagonal and zeros elsewhere.

A diagonal matrix is a square matrix with non-zero elements only on its main diagonal.

An identity matrix is a square matrix with ones on the diagonal and zeros elsewhere, serving as the multiplicative identity in matrix operations.

A low-rank matrix has a rank significantly less than its dimensions, allowing for efficient data representation and approximation.

A matrix norm is a mathematical tool used to measure the size or length of a matrix.