|
Action:
|
Gets the cross product of two gvectors.
|
|
|
Filename:
|
kern/kern_scm/gvec_scm.cxx
|
|
|
Syntax:
|
(gvector:cross gvector1 gvector2)
|
|
|
Arg Types:
|
gvector1
|
gvector
|
|
gvector2
|
gvector
|
|
|
Returns:
|
gvector
|
|
|
Description:
|
If the
i, j, k components of vector
a are <a1,
a2,
a3>, and the
i, j, k components of vector
b are <b1,
b2,
b3>, the cross product
a x
b is:
|
|
|
|
|a2 a3
|
|
|
|
|a1 a3
|
|
|
|
|a1 a2
|
|
|
|
a x b =
|
|
|
|
|i
|
-
|
|
|
|
|j
|
+
|
|
|
|
|k
|
|
|
|
|b2 b3
|
|
|
|
|b1 b3
|
|
|
|
|b1 b2
|
|
|
|
|
a x b =
|
|
[(a2)(b3)-(b2)(a3)]i
|
|
|
|
|
- [(a1)(b3)-(b1)(a3)]j
|
|
|
|
|
+ [(a1)(b2)-(b1)(a2)]k
|
|
|
The resulting cross product vector is perpendicular to both input vectors. The cross product
a x b is not the same as the cross product
b x a; they point in opposite directions (180 degrees from one another).
|
|
|
gvector1 specifies the first vector.
|
|
|
gvector2 specifies the second vector.
|
|
|
Example:
|
; gvector:cross
|
|
; Compute the cross product of two gvectors.
|
|
(gvector:cross (gvector 2 2 2) (gvector 5 3 8))
|
|
;; #[gvector 10 -6 -4]
|
|
(gvector:cross (gvector 5 3 8) (gvector 2 2 2))
|
|
;; #[gvector -10 6 4]
|