F150: Direct or Tensor Matrix Product

Author(s): K.S. Kölbig	Library: MATHLIB
Submitter:	Submitted: 15.09.1978
Language: Fortran	Revised:

Subroutine subprogram MXDIPR computes the direct (sometimes called tensor, or Kronecker) product of two matrices A and B. Let ; ; then with . C has rows and columns. If, in particular, A and B are square matrices, C is also square.

Structure:

SUBROUTINE subprogram
User Entry Names: MXDIPR

Usage:

    CALL MXDIPR(A,B,C,IAD,JBD,IJD,IA,KA,JB,LB)

A,B

(REAL) Matrices A and B.

C

(REAL) On exit, C contains the direct product .

IAD

(INTEGER) First dimension of A.

JBD

(INTEGER) First dimension of B.

IJD

(INTEGER) First dimension of C.

IA,KA

(INTEGER) Number of rows, columns of A.

JB,LB

(INTEGER) Number of rows, columns of B.

Restrictions:

A, B, C must not overlap.

Error handling:

If IA or KA or JB or LB are equal to zero, the subprogram acts as do-nothing.

Examples:

    DIMENSION A(2,2),B(2,2),C(4,4)
    ...
    CALL MXDIPR(A,B,C,2,2,4,2,2,2,2)

assuming

would set

References:

1. E.P. Wigner, Group Theory, (Academic Press, New York 1959) 17
2. W.I. Smirnow, Lehrgang der höheren Mathematik, Vol. III.1, (Deutscher Verlag der Wissenschaften, Berlin 1954) 221