SLA_MXV
Apply 3D Rotation

ACTION:
 Multiply a 3vector by a rotation matrix (single precision).

CALL:
CALL sla_MXV (RM, VA, VB)
GIVEN:
RM  R(3,3)  rotation matrix 

VA  R(3)  vector to be rotated 

RETURNED:

NOTES:


(1)
 This routine performs the operation:
where a and b are the 3vectors VA and VB respectively, and M is the
$3\times 3$
matrix RM.

(2)
 The main function of this routine is apply a rotation; under these circumstances,
$$M
is a proper real orthogonal matrix.

(3)
 To comply with the ANSI Fortran 77 standard, VA and VB must not be the same array. The
routine is, in fact, coded so as to work properly with many Fortran compilers even if this
rule is violated, something that is not, however, recommended.