kron .*.

Arguments

A, B

Arrays of size (a1, a2, ..) and (b1, b2, ..), with any number of dimensions. If A or B is sparse, the other one can't be an hypermatrix.

Supported encodings and types: integer, real, complex, polynomial, rational, sparse.

P

Array of A and B data type, and of size (a1*b1, a2*b2, ..). If A or B is sparse, P is sparse.

Description

kron(A,B) or A .*. B returns the Kronecker tensor product of two matrices or hypermatricesA and B. The resulting matrix has the following block form:

If A is a m x n matrix and B a p x q x r hypermatrix then A.*.B is a (m*p) x (n*q) x (1*r) hypermatrix.

Examples

A = [1 3 ; 2 4]
B = [1 10 100]
kron(A, B)
A .*. B
B .*. A

--> A = [1 3 ; 2 4]
 A  =
   1.   3.
   2.   4.

--> B = [1 10 100]
 B  =
   1.   10.   100.

--> kron(A, B)
 ans  =
   1.   10.   100.   3.   30.   300.
   2.   20.   200.   4.   40.   400.

--> A .*. B
 ans  =
   1.   10.   100.   3.   30.   300.
   2.   20.   200.   4.   40.   400.

--> B .*. A
 ans  =
   1.   3.   10.   30.   100.   300.
   2.   4.   20.   40.   200.   400.

With sparse matrices:

P = [-1 0 1 10] .*. sparse([0 1 2])
full(P)

--> P = [-1 0 1 10] .*. sparse([0 1 2])
 P  =
(  1,  12) sparse matrix
(  1,  2)    -1.
(  1,  3)    -2.
(  1,  8)     1.
(  1,  9)     2.
(  1,  11)    10.
(  1,  12)    20.

--> full(P)
 ans  =
   0.  -1.  -2.   0.   0.   0.   0.   1.   2.   0.   10.   20.

With complex numbers:

A = [-1 1 ; -%i %i]
A .*. A

--> A = [-1 1 ; -%i %i]
 A  =
  -1.     1.
  -i      i

--> A .*. A
 ans  =
   1.    -1.    -1.     1.
   i     -i     -i      i
   i     -i     -i      i
  -1.     1.     1.    -1.

With hypermatrices:

b = matrix(1:24, [4 3 2]);

// row .*. hypermat
a = 1:2, b
a.*.b

// hypermat .*. row
b,a
b .*. a

// column .*. hypermat
a = [1;2], b
a.*.b

// matrix .*. hypermat
a = [-1 -2; 2 1], b
a.*.b

// hypermat .*. hypermat
a = matrix([-1,-2, 1 2], [1 2 2]), b
a.*.b

See Also

• kron .\. ./. — Kronecker left and right divisions
• star — (*) multiplication operator
• prod — product of array elements
• cumprod — cumulative product of array elements
• repmat — Replicate and tile an array

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