kronecker-product ( m1 m2 -- m )
Extra matrix operations

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Vocabulary
math.matrices.extras

Inputs

m1	a matrix
m2	a matrix

Outputs

m

a matrix

Word description
Calculates the Kronecker product of two matrices. This product can be described as a generalization of the vector-based outer-product to matrices. The Kronecker product gives the matrix of the tensor product with respect to a standard choice of basis.

Notes

•	This word is the matrix variant of outer-product.
•	This word is intended for use with "flat" (2-dimensional) matrices.
•	This word assumes that elements of the input matrix are compatible with the following words: * ( x y -- z )

Examples

USING: math.matrices.extras prettyprint ; { { 1 2 } { 3 4 } } { { 0 5 } { 6 7 } } kronecker-product .
{ { 0 5 0 10 } { 6 7 12 14 } { 0 15 0 20 } { 18 21 24 28 } }

Definition

USING: kernel math.matrices sequences ;

IN: math.matrices.extras

: kronecker-product ( m1 m2 -- m )
    [ n*m ] curry [ map ] curry map stitch stitch ;