- Abstract
Compute the cross product of two 3-dimensional vectors.
- Required_Reading
None.
- Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
v1 I Left hand vector for cross product.
v2 I Right hand vector for cross product.
vout O Cross product v1xv2.
vout can overwrite either v1 or v2.
- Detailed_Input
v1 This may be any 3-dimensional vector. Typically, this
might represent the (possibly unit) vector to a planet,
sun, or a star which defines the orientation of axes of
some coordinate system.
v2 Ditto.
- Detailed_Output
vout This variable represents the cross product of v1 and v2.
vout may overwrite v1 or v2.
- Parameters
None.
- Particulars
vcrss_c calculates the three dimensional cross product of two
vectors according to the definition. The cross product is stored
in a buffer vector until the calculation is complete. Thus vout
may overwrite v1 or v2 without interfering with intermediate
computations.
If v1 and v2 are large in magnitude (taken together, their
magnitude surpasses the limit allow by the computer) then it may
be possible to generate a floating point overflow from an
intermediate computation even though the actual cross product
may be well within the range of double precision numbers.
vcrss_c does NOT check the magnitude of v1 or v2 to insure that
overflow will not occur.
- Examples
v1 v2 vout (=v1Xv2)
-----------------------------------------------------------------
(0, 1, 0) (1, 0, 0) (0, 0, -1)
(5, 5, 5) (-1, -1, -1) (0, 0, 0)
- Restrictions
No checking of v1 or v2 is done to prevent floating point
overflow. The user is required to determine that the magnitude
of each component of the vectors is within an appropriate range
so as not to cause floating point overflow. In almost every case
there will be no problem and no checking actually needs to be
done.
- Exceptions
Error free.
- Files
None.
- Author_and_Institution
W.M. Owen (JPL)
E.D. Wright (JPL)
- Literature_References
None.
- Version
-CSPICE Version 1.1.0, 22-OCT-1998 (NJB)
Made input vectors const.
-CSPICE Version 1.0.1, 06-MAR-1998 (EDW)
Minor header correction. Added use of MOVED.
-CSPICE Version 1.0.0, 08-FEB-1998 (EDW)
- Index_Entries
vector cross product
- Link to routine source