mat.dirprod {dae} R Documentation

## Forms the direct product of two matrices

### Description

Form the direct product of the m \times n matrix A and the p \times q matrix B. It is also called the Kroneker product and the right direct product. It is defined to be the result of replacing each element of A, a_{ij}, with a_{ij}\bold{B}. The result matrix is mp \times nq.

The method employed uses the rep function to form two mp \times nq matrices: (i) the direct product of A and J, and (ii) the direct product of J and B, where each J is a matrix of ones whose dimensions are those required to produce an mp \times nq matrix. Then the elementwise product of these two matrices is taken to yield the result.

### Usage

mat.dirprod(A, B)

### Arguments

 A The left-hand matrix in the product. B The right-hand matrix in the product.

### Value

An mp \times nq matrix.

### Author(s)

Chris Brien

matmult, mat.dirprod
    col.I <- mat.I(order=4)